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Berkeley Sensor & Actuator Center
 

The Berkeley Sensor & Actuator Center (BSAC) is the Graduated National Science Foundation Industry/University Cooperative Research Center for Microsensors and Microactuators. We conduct industry-relevant, interdisciplinary research on micro- and nano-scale sensors, moving mechanical elements, microfluidics, materials, processes & systems that take advantage of progress made in integrated-circuit, bio, and polymer technologies.

BSAC Current Active Projects as of November 17, 2017

Number of records: 83
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PROJECT MATERIALS
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PROJECT TITLEADVISOR
1NanoTechnology: Materials, Processes & DevicesBPN856BPN856 WebsiteBroadly-Tunable Laser with Self-Imaging Three-Branch Multi-Mode InterferometerMing C. Wu
2NanoTechnology: Materials, Processes & DevicesBPN825BPN825 WebsiteDirect On-Chip Optical Synthesizer (DODOS)Ming C. Wu
4NanoPlasmonics, Microphotonics & ImagingBPN751BPN751 WebsiteLarge-Scale Silicon Photonic MEMS Switch with Sub-Microsecond Response TimeMing C. Wu
5NanoPlasmonics, Microphotonics & ImagingBPN721BPN721 WebsiteNon-Linear FMCW Lidar Using Resampling Methods for Long Range and High ResolutionMing C. Wu
6NanoPlasmonics, Microphotonics & ImagingBPN703BPN703 WebsiteDirectly Modulated High-Speed nanoLED Utilizing Optical Antenna Enhanced Light EmissionMing C. Wu
7NanoPlasmonics, Microphotonics & ImagingBPN869BPN869 WebsiteEfficient Waveguide-Coupling of Electrically Injected Optical Antenna Based nanoLED New ProjectMing C. Wu
8NanoPlasmonics, Microphotonics & ImagingBPN458BPN458 WebsiteOptical Antenna-Based nanoLEDMing C. Wu, Ali Javey
9NanoPlasmonics, Microphotonics & ImagingBPN788BPN788 WebsiteMEMS-Actuated Grating-based Optical Phased Array for LIDARMing C. Wu
10Physical Sensors & DevicesBPN872BPN872 WebsiteCOMPACT VOLTAGE SENSOR FOR POWER-LINES New ProjectRichard M. White
11Physical Sensors & DevicesBPN868BPN868 WebsiteSelf-Cleaning Mass Sensor for Particulate Matter MonitorsRichard M. White, Paul K. Wright
12Physical Sensors & DevicesBPN801BPN801 WebsiteELECTROMAGNETIC ENERGY HARVESTER FOR ATMOSPHERIC SENSORS ON OVERHEAD POWER DISTRIBUTION LINESRichard M. White, Paul K. Wright
13Physical Sensors & DevicesBPN826BPN826 WebsiteAutonomous Flying MicrorobotsKristofer S.J. Pister
14Physical Sensors & DevicesBPN873BPN873 WebsiteMEMS Filament Motors New ProjectKristofer S.J. Pister
15Physical Sensors & DevicesBPN857BPN857 WebsiteMiniature Autonomous RocketsKristofer S.J. Pister
16Wireless, RF & Smart DustBPN735BPN735 WebsiteWalking Silicon MicrorobotsKristofer S.J. Pister
17Wireless, RF & Smart DustBPN858BPN858 WebsiteZero Insertion Force MEMS Socket for Microrobotics AssemblyKristofer S.J. Pister
18Wireless, RF & Smart DustBPN744BPN744 WebsiteSelf-Destructing SiliconKristofer S.J. Pister, Michel M. Maharbiz
19Wireless, RF & Smart DustBPN803BPN803 WebsiteSingle Chip MoteKristofer S.J. Pister, Ali M. Niknejad
20Wireless, RF & Smart DustBPN859BPN859 WebsiteUHF Channel-Selecting Bandpass FilterClark T.-C. Nguyen
21Wireless, RF & Smart DustBPN828BPN828 WebsiteZero Quiescent Power Micromechanical ReceiverClark T.-C. Nguyen
22Wireless, RF & Smart DustBPN814BPN814 WebsiteUHF Capacitive-Gap Transduced Resonators With High Cx/CoClark T.-C. Nguyen
23Wireless, RF & Smart DustBPN861BPN861 WebsiteFully Integrated MEMS-Based Super-Regenerative TransceiverClark T.-C. Nguyen
24Wireless, RF & Smart DustBPN701BPN701 WebsiteBridged Micromechanical FiltersClark T.-C. Nguyen
25NanoTechnology: Materials, Processes & DevicesBPN867BPN867 WebsiteFully Integrated CMOS-Metal MEMS SystemsClark T.-C. Nguyen
26Wireless, RF & Smart DustBPN865BPN865 WebsiteCMOS-Assisted Resoswitch ReceiversClark T.-C. Nguyen
27Wireless, RF & Smart DustBPN866BPN866 WebsiteWide-Bandwidth UHF Bandpass FiltersClark T.-C. Nguyen
28Wireless, RF & Smart DustBPN864BPN864 WebsiteMicromechanical Resonator Waveform SynthesizerClark T.-C. Nguyen
29Package, Process & MicroassemblyBPN354BPN354 WebsiteThe Nanoshift Concept: Innovation through Design, Development, Prototyping and Fabrication of MEMS, Microfluidics, Nano- and Clean TechnologiesMichael D. Cable
30MicropowerBPN874BPN874 WebsiteCharge Pumping with Finger Capacitance for Body Energy Harvesting New ProjectMichel M. Maharbiz
31BioMEMSBPN718BPN718 WebsiteDirect Electron-Mediated Control of Hybrid Multi-Cellular RobotsMichel M. Maharbiz
32BioMEMSBPN853BPN853 WebsiteTethered Bacteria-Based BiosensingMichel M. Maharbiz
33Physical Sensors & DevicesBPN765BPN765 WebsiteFull-Field Strain Sensor for Hernia Mesh RepairsMichel M. Maharbiz
34Physical Sensors & DevicesBPN714BPN714 WebsiteImpedance Sensing Device to Monitor Pressure UlcersMichel M. Maharbiz
35Physical Sensors & DevicesBPN780BPN780 WebsiteImpedance Spectroscopy to Monitor Fracture HealingMichel M. Maharbiz
36Wireless, RF & Smart DustBPN844BPN844 WebsiteWireless Sub-Millimeter Temperature Sensor for Continuous Temperature Monitoring in TissueMichel M. Maharbiz
37BioMEMSBPN816BPN816 WebsiteCytokine Fast DetectionMichel M. Maharbiz
38BioMEMSBPN716BPN716 WebsiteUltrasonic Wireless Implants for Neuro-ModulationMichel M. Maharbiz
39BioMEMSBPN795BPN795 WebsiteAn Implantable Micro-Sensor for Cancer SurveillanceMichel M. Maharbiz
41Wireless, RF & Smart DustBPN848BPN848 WebsiteHighly Integrated, Compact Wearable Ultrasound System for Chronic BiosensingMichel M. Maharbiz, Bernhard E. Boser
42BioMEMSBPN573BPN573 WebsiteFabrication and Microassembly of a High-Density Carbon Fiber Neural Recording ArrayMichel M. Maharbiz, Kristofer S.J. Pister
43Wireless, RF & Smart DustBPN871BPN871 WebsiteAn Ultrasonic Implantable for Continuous In Vivo Monitoring of Tissue Oxygenation New ProjectMichel M. Maharbiz, Mekhail Anwar
44BioMEMSBPN884BPN884 WebsiteAnisotropic Proton Transport in Artificially Aligned Collagen Fiber New ProjectLuke P. Lee
45BioMEMSBPN829BPN829 WebsiteIntegrated Multiplexed Optical Microfluidic System (iMOMs) for Dengue DiagnosisLuke P. Lee
46NanoPlasmonics, Microphotonics & ImagingBPN809BPN809 WebsitePhotonic Cavity Bioreactor for High-throughput Screening of MicroalgaeLuke P. Lee
47NanoTechnology: Materials, Processes & DevicesBPN881BPN881 WebsiteStrain-engineered growth of two-dimensional materials New ProjectAli Javey
48Physical Sensors & DevicesBPN818BPN818 WebsiteFully-Integrated Wearable Sensor Arrays for Multiplexed In Situ Perspiration AnalysisAli Javey
49Physical Sensors & DevicesBPN770BPN770 WebsiteChemical Sensitive Field Effect Transistor (CS-FET)Ali Javey
50Physical Sensors & DevicesBPN883BPN883 WebsiteMicrochannel contacting of crystalline silicon solar cells New ProjectAli Javey
51NanoTechnology: Materials, Processes & DevicesBPN704BPN704 WebsiteVapor-Liquid-Solid Growth of Polycrystalline Indium Phosphide Thin Films on MetalAli Javey
52Physical Sensors & DevicesBPN879BPN879 WebsiteA wearable impedance-based microfluidic sensor for sweat rate monitoring New ProjectAli Javey
53NanoTechnology: Materials, Processes & DevicesBPN822BPN822 WebsiteMonolayer Semiconductor OptoelectronicsAli Javey
54NanoTechnology: Materials, Processes & DevicesBPN862BPN862 WebsiteMoS2 Transistors with 1-Nanometer Gate LengthsAli Javey
55Physical Sensors & DevicesBPN608BPN608 WebsiteFM GyroscopeBernhard E. Boser
56Physical Sensors & DevicesBPN852BPN852 WebsiteFrequency to Digital Converter for FM GyroscopesBernhard E. Boser
57BioMEMSBPN685BPN685 WebsiteReal-Time Intraoperative Fluorescence Imager for Microscopic Residual Tumor in Breast CancerBernhard E. Boser, Mekhail Anwar
58BioMEMSBPN882BPN882 WebsiteAn Ultra-Thin Molecular Imaging Skin for Intraoperative Cancer Detection Using Time-Resolved CMOS Sensors New ProjectBernhard E. Boser, Mekhail Anwar
59NanoTechnology: Materials, Processes & DevicesBPN875BPN875 WebsiteTransfer-Free Synthesis of Graphene on Insulating Substrates New ProjectRoya Maboudian
60NanoPlasmonics, Microphotonics & ImagingBPN878BPN878 WebsiteSuper-resolution synthesis of nontrivial heterogeneous nanoparticles assisted by surface plasmons New ProjectRoya Maboudian, Carlo Carraro
61NanoTechnology: Materials, Processes & DevicesBPN843BPN843 WebsiteNon-Enzymatic Electrochemical Sensors Based on Wearable Carbon TextileRoya Maboudian, Carlo Carraro
62NanoTechnology: Materials, Processes & DevicesBPN835BPN835 WebsiteSilicon Carbide Passivated Electrode for Thermionic Energy ConversionRoya Maboudian, Carlo Carraro
63Physical Sensors & DevicesBPN876BPN876 WebsiteMetal-organic frameworks: A highly tunable class of materials for chemical sensing with high selectivity New ProjectRoya Maboudian, Carlo Carraro, Ali Javey
64Physical Sensors & DevicesBPN743BPN743 WebsiteHighly Responsive pMUTsLiwei Lin
65MicropowerBPN782BPN782 WebsiteFlexible load-bearing energy storage fabricsLiwei Lin
66Physical Sensors & DevicesBPN799BPN799 Website3D Printed MicrosensorsLiwei Lin
67NanoTechnology: Materials, Processes & DevicesBPN672BPN672 WebsiteSolar Hydrogen Production by Photocatalytic Water SplittingLiwei Lin
68MicrofluidicsBPN774BPN774 WebsiteApplications of 3D Printed Integrated Microfluidic Circuitry, Finger-Powered Pumps, and MixersLiwei Lin
69MicrofluidicsBPN846BPN846 Website3D Printed Biomedical and Diagnostic SystemsLiwei Lin
70Wireless, RF & Smart DustBPN840BPN840 WebsiteW-Band Additive Vacuum ElectronicsLiwei Lin
71MicropowerBPN855BPN855 WebsiteFlexible Sensors and Energy HarvestersLiwei Lin
72Physical Sensors & DevicesBPN877BPN877 WebsitePulse Acquisition and Diagnosis for Health Monitoring New ProjectLiwei Lin
73MicropowerBPN742BPN742 WebsiteNovel Methods to Synthesis Transition Metal Dichalcogenide and Transition Metal Carbide for Energy Storage ApplicationsLiwei Lin
74NanoTechnology: Materials, Processes & DevicesBPN860BPN860 WebsiteFoldable Paper Electronics by Direct-Write Laser PatterningLiwei Lin
75Physical Sensors & DevicesBPN772BPN772 WebsiteGraphene for Room Temperature Gas SensorsLiwei Lin
76BioMEMSBPN870BPN870 WebsiteHot Embossed Thermoplastic Bubble-Actuated Micropump New ProjectDorian Liepmann
77MicrofluidicsBPN863BPN863 WebsiteIn Situ Gold Plating of Microfluidic DevicesDorian Liepmann
78MicrofluidicsBPN839BPN839 WebsiteFlow Control in Plastic Microfluidic Devices Using Thermosensitive GelsDorian Liepmann
79BioMEMSBPN729BPN729 WebsiteDevelopment of Microfluidic Devices with Embedded Microelectrodes using Electrodeposition and Hot EmbossingDorian Liepmann
80Physical Sensors & DevicesBPN851BPN851 WebsiteHigh Fill Factor Piezoelectric Micromachined Ultrasonic Transducers on Transparent SubstratesDavid A. Horsley
81Physical Sensors & DevicesBPN880BPN880 WebsiteSynchronization in a Micromachined Resonators New ProjectDavid A. Horsley
82Physical Sensors & DevicesBPN785BPN785 WebsiteScandium AlN (ScAlN) for MEMSDavid A. Horsley
83Physical Sensors & DevicesBPN628BPN628 WebsiteNovel Ultrasonic Fingerprint Sensor Based on High-Frequency Piezoelectric Micromachined Ultrasonic Transducers (PMUTs)David A. Horsley
84Physical Sensors & DevicesBPN849BPN849 WebsiteLarge-Amplitude PZT PMUTsDavid A. Horsley
85Physical Sensors & DevicesBPN817BPN817 WebsiteUltra-Low Power AlN MEMS-CMOS Microphones and AccelerometersDavid A. Horsley

Project Abstracts

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Table of Projects
NanoTechnology: Materials, Processes & Devices
Project IDBPN856
Project Title Broadly-Tunable Laser with Self-Imaging Three-Branch Multi-Mode Interferometer
Status Continuing
Funding Source Industry
Keywords WDM, tunable lasers, single-mode lasers
Researchers Guan-Lin Su
Abstract Tunable lasers with high SMSRs are cost-effective solutions to replace multiple DFB lasers as the light source for WDM systems. Interferometer- based lasers, such as C3 and Y- lasers, have advantages over grating- and ring-resonator-based lasers in terms of cost and fabrication complexities; however, a large optical path difference between the two arms is required for high SMSRs but it defeats the Vernier effect and reduces the wavelength tuning range. In our proposed three-branch MMI laser, two tuning arms with similar lengths ensure a wide tuning range, and an additional long arm provides extra optical interference and increases the SMSR. In this project, our designed laser can be optimized to be single-mode across the entire C-band, and the use of a self-imaging MMI avoids additional losses that would potentially increase the threshold. Based on our simulation, the laser wavelength of the device can be electrically tuned over 30 nm with a 100-GHz ITU channel spacing. It is expected that, upon the completion of the project, the developed tunable laser can serve as a low-cost solution for datacom and telecom applications.
Contact Information gsu2@berkeley.edu
Advisor Ming C. Wu

 
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NanoTechnology: Materials, Processes & Devices
Project IDBPN825
Project Title Direct On-Chip Optical Synthesizer (DODOS)
Status Continuing
Funding Source DARPA
Keywords
Researchers Jean-Etienne Tremblay, Guan-Lin Su, Kyungmok Kwon
Abstract The advent of precise microwave frequency synthesis in the 1940’s enabled a disruptive revolution in the capabilities enabled by microwave technology, including wireless and wireline communications, RADAR, electronic warfare, and atomic sensors and timing technology. It is envisioned that the DODOS program will advance a similar transformative revolution based on ubiquitous optical frequency synthesis technology. Laboratory-scale optical frequency synthesis was successfully realized in 1999 with the invention of self-referenced optical frequency combs based on femto-second pulse-length mode-locked laser sources. This has led to optical synthesizers with frequency accuracy better than 10e-19 and demonstration of optical clocks with stability floor below 2x10e-18. However, such systems are large, costly, and thereby confined to laboratory use. Recent development of Kerr combs generated in microresonators, as well as chip-scale mode-locked lasers, enable the development of a microscale self-referenced optical frequency comb with performance rivaling that of laboratory-scale systems. Combined with recent progress in on-chip photonic waveguides and photonic crystals, widely-tunable laser sources, and optical modulators, along with advances in on-chip optical-CMOS heterogeneous integration, it is now possible to develop a robust and deployable single-chip integrated optical frequency synthesizer. It is expected that the DODOS program will enable low-cost and high performance optical frequency control with the ubiquity of microwave synthesis.
Contact Information jetremblay@berkeley.edu, gsu2@berkeley.edu, kwon0512@berkeley.edu
Advisor Ming C. Wu

 
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Table of Projects
NanoPlasmonics, Microphotonics & Imaging
Project IDBPN751
Project Title Large-Scale Silicon Photonic MEMS Switch with Sub-Microsecond Response Time
Status Continuing
Funding Source NSF
Keywords optical switch, silicon photonics, large scale, fast, small footprint
Researchers Johannes Henriksson, Jianheng Luo, Kyungmok Kwon
Abstract We developed a new architecture suitable for building a large-scale optical switch with fast response time. We have demonstrated switches with a scale of 64x64 and speed of sub- microsecond using our new architecture. The switch architecture consists of an optical crossbar network with MEMS-actuated couplers and is implemented on a silicon photonics platform. Thanks to high integration density of the silicon photonics platform, we could integrate 64x64 switch on an area less than 1cm x 1cm. To our knowledge this is the largest monolithic switch, and the largest silicon photonic integrated circuit, reported to date. The passive matrix architecture of our switch is fundamentally more scalable than that of multistage switches. We believe that our switch architecture can be scaled-up to larger than 200x200.
Contact Information jhenriksson@berkeley.edu
Advisor Ming C. Wu

 
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Table of Projects
NanoPlasmonics, Microphotonics & Imaging
Project IDBPN721
Project Title Non-Linear FMCW Lidar Using Resampling Methods for Long Range and High Resolution
Status Continuing
Funding Source DARPA
Keywords lidar, VCSEL, FMCW, metrology, 3D imaging
Researchers Phillip A.M. Sandborn
Abstract Range-finding sensors have applications that span several industries and markets, from metrology to robotic control. Frequency-modulated continuous-wave lidar has been proven effective in providing high depth resolution, but suffers from limited range due to the limited coherence length of tunable laser sources. Implementations typically require expensive lasers with large coherence length or complex feedback to linearize tunable laser sweeps and extend coherence length. Instead, we use resampling methods to linearize laser sweeps and reduce laser phase noise, all in post-processing, thus reducing the need for precision feedback control or expensive tunable laser hardware. We have demonstrated sub-millimeter resolution at free-space distances >20-meters with 1-inch receiving aperture. In addition, we present a demonstration of this technology which approaches reasonable 3D image acquisition speeds with sub-mm depth precision. Use of RAID and FPGA systems can help approach real- time frame-rates for 3D imaging.
Contact Information sandborn@berkeley.edu
Advisor Ming C. Wu

 
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Table of Projects
NanoPlasmonics, Microphotonics & Imaging
Project IDBPN703
Project Title Directly Modulated High-Speed nanoLED Utilizing Optical Antenna Enhanced Light Emission
Status Continuing
Funding Source Federal
Keywords nano-photonics, optical antenna, photonics, optical interconnect, nanotechnology, optoelectronics, plasmonics
Researchers Seth A. Fortuna, Kevin Han, Nicolas Andrade
Abstract Traditional semiconductor light emitting diodes (LEDs) have low modulation speed because of long spontaneous emission lifetime. Spontaneous emission in semiconductors (and indeed most light emitters) is an inherently slow process owing to the size mismatch between the dipole length of the optical dipole oscillators responsible for light emission and the wavelength of the emitted light. More simply stated: semiconductors behave as a poor antenna for its own light emission.
By coupling a semiconductor at the nanoscale to an external antenna, the spontaneous emission rate can be dramatically increased alluding to the exciting possibility of an LED that can be directly modulated faster than the laser. In this project, we plan to demonstrate an antenna- enhanced nanoscale semiconductor light emitting diode (nanoLED) with direct modulation rate >50 GHz, exceeding the bandwidth of the semiconductor laser. Such an nanoLED is well-suited as a light source for on-chip optical communication where small size, fast speed, and high efficiency are needed to achieve the promised benefit of reduced power consumption of on-chip optical interconnect links compared with less efficient electrical interconnect links.
Contact Information fortuna@eecs.berkeley.edu
Advisor Ming C. Wu

 
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NanoPlasmonics, Microphotonics & Imaging
Project IDBPN869 New Project
Project Title Efficient Waveguide-Coupling of Electrically Injected Optical Antenna Based nanoLED
Status New
Funding Source Federal
Keywords light emitting diode, waveguide coupling, optical antenna
Researchers Nicolas M. Andrade, Seth A. Fortuna, Kevin Han
Abstract Optical interconnects require fast and efficient electrically-injected nanoscale light sources that can be coupled efficiently to a low-loss photonic waveguide. The spontaneous emission rate can be increased by coupling the active region of a nanoscale emitter to an optical antenna, which would allow for modulation rates > 50 GHz. The aim of this project is to demonstrate efficient waveguide coupling of an optical antenna to a single mode waveguide.
Contact Information nicolas_andrade@berkeley.edu
Advisor Ming C. Wu

 
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Table of Projects
NanoPlasmonics, Microphotonics & Imaging
Project IDBPN458
Project Title Optical Antenna-Based nanoLED
Status Continuing
Funding Source Federal
Keywords Plasmonics, Laser, Light Emitting Diode, Nanophotonics, Nanocavity, Optical Interconnects, Transition Metal Dichalcogenides
Researchers Kevin Han, Seth Fortuna, Sujay Desai, Matin Amani
Abstract Spontaneous emission has been considered slower and weaker than stimulated emission. As a result, light-emitting diodes (LEDs) have only been used in applications with bandwidth < 1 GHz. Spontaneous emission is inefficient because the radiating dipole is much smaller than the wavelength and such short dipoles are poor radiators. By attaching an optical antenna to the radiating dipole at the nanoscale, the emission rate can be significantly increased enabling high modulation bandwidths theoretically >100 GHz. This project focuses on the physical demonstration of this new type of nanophotonic device. Current fabrication and experimental results of devices using transition metal dichalcogenides (TMDs) as an emitter material will be presented. Fundamental limits of rate enhancement will also be discussed.
Contact Information kyh@eecs.berkeley.edu
Advisor Ming C. Wu, Ali Javey

 
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Table of Projects
NanoPlasmonics, Microphotonics & Imaging
Project IDBPN788
Project Title MEMS-Actuated Grating-based Optical Phased Array for LIDAR
Status Continuing
Funding Source Industry
Keywords Lidar, Optical MEMS, Beamsteering
Researchers Youmin Wang
Abstract We aim to integrate the OPA MEMS system into the application of automobile navigation, which is currently primarily dominated by opto-mechanical scanning based systems. Opto-mechanical scanning devices are usually bulky and relatively slow, and cannot provide the steering speeds and versatility necessary for many applications. In drawing from phased array concepts that revolutionized RADAR technology by providing a compact, agile alternative to mechanically steered technology, the OPA based LIDAR program seeks to integrate thousands of closely packed optical emitting facets, precise relative electronic phase control of these facets, and all within a very small form factor. Comparing with other competing LIDAR system, the OPA based LIDAR system will have multiple degrees of freedom for phase control which enables not only agile beam steering but also beam forming and multiple beam generation, greatly expanding the diversity of applications. Traditional optical phased arrays (OPA) are made of liquid crystal phase shifters, piston mirrors, and optical waveguide arrays. The liquid crystal OPA has slow response time. MEMS OPA with piston mirrors has fast response time. However, realization of OPA with large field of view is challenging because it requires small pitch in the phased array. Recently, it was reported that optical phase shift is controlled by moving a grating element in the lateral direction. However, the widths of the phase shifters are limited by the size of the actuators. In this project, the actuators are integrated underneath the diffractive elements so OPA with high fill factor and small pitch can be realized. Such OPA will have large field of view and high optical efficiency.
Contact Information youmin.wang@berkeley.edu, wu@eecs.berkeley.edu
Advisor Ming C. Wu

 
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Table of Projects
Physical Sensors & Devices
Project IDBPN872 New Project
Project Title COMPACT VOLTAGE SENSOR FOR POWER-LINES
Status New
Funding Source BSAC Member Fees
Keywords Power line voltage sensors
Researchers Duy-Son Nguyen
Abstract This project is enable to measure of the line-to-line voltages of distribution and transmission power-lines by using very compact and inexpensive sensors that operate at low voltages. On a two-wire power-line the measurement devices are mounted on only one of the lines. The devices can also be applied in open-air power substations and in buildings where high-voltage power-lines, e.g. 12,400 AC Volts, are used.
Contact Information nguyen.duyson@berkeley.edu, rwhite@berkeley.edu
Advisor Richard M. White

 
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Table of Projects
Physical Sensors & Devices
Project IDBPN868
Project Title Self-Cleaning Mass Sensor for Particulate Matter Monitors
Status New
Funding Source BSAC Member Fees
Keywords aerosol, particulate matter, deposition, aerosol resuspension, aerosol speciation, PM2.5, PM10, carbon, dust, pollen, FTIR, IR, soot, spore, bacteria, diesel, FBAR
Researchers Zhiwei Wu
Abstract When people inhale small particles, such as soot, they may develop pulmonary, cardiac and neural problems, and millions may die prematurely. Therefore, there is need for widely accessible particulate-matter monitors to enable individuals to avoid areas of high particulate concentration. We propose to test means conceived for cleaning the surfaces of the particle mass-measuring sensors after each particulate deposition, as well as recently reported spectroscopic means for determining the chemical compositions of deposited particles.
Contact Information zway@berkeley.edu, rwhite@eecs.berkeley.edu, paulwright@ berkeley.edu
Advisor Richard M. White, Paul K. Wright

 
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Physical Sensors & Devices
Project IDBPN801
Project Title ELECTROMAGNETIC ENERGY HARVESTER FOR ATMOSPHERIC SENSORS ON OVERHEAD POWER DISTRIBUTION LINES
Status Continuing
Funding Source BSAC Member Fees
Keywords Energy harvester, power system sensors, atmospheric and environmental sensors, overhead power distribution lines
Researchers Zhiwei Wu
Abstract The purposes of this project are to develop inexpensive, easily-installed energy harvesters for mounting on overhead or underground power distribution lines in order (1) to power sensors that evaluate and report on the functioning of the power system, and (2) to power co-located environmental sensors, such as particulate-matter monitors and gas sensors, that can transmit their measurements to nearby personal cellphones.
Contact Information zway@berkeley.edu, rwhite@eecs.berkeley.edu, paulwright@berkeley.edu
Advisor Richard M. White, Paul K. Wright

 
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Physical Sensors & Devices
Project IDBPN826
Project Title Autonomous Flying Microrobots
Status Continuing
Funding Source BSAC Member Fees
Keywords electrohydrodynamics, microrobotics, ionocraft, ion thrust, MAV
Researchers Daniel S. Drew, Craig Schindler
Abstract Even as autonomous flying drones enter the mainstream, there has been no strong push for miniaturization by industry. Among the state of the art academic research on pico air vehicles, the majority has focused on biomimetic flight mechanisms (e.g. flapping wings). This project looks to develop a new microfabricated transduction mechanism for flying microrobots with the goal of opening up the application space beyond that allowed by the industry-standard quadcoptor. The proposed mechanism, electrohydrodynamic (EHD) force, functions silently and with no moving parts, directly converting ion current to induced air flow. Microfabricated silicon electrodes are currently being used to create devices with thrust to weight ratios in excess of 15. Microrobots with four individually addressable thrusters have been assembled that mass about 10mg and measure less than 2cm on a side, with the capability of takeoff while tethered to a power supply. Rudimentary attitude control has been shown by selective actuation of two of the four thrusters. Current work is exploring methods to decrease the operating voltage of the robot, improve fabrication and assembly repeatability, and add on-board sensing. Ultimately, integration with a low power control and communications platform will yield a truly autonomous flying microrobot powered by ion thrusters – the ionocraft.
Contact Information ddrew73@eecs.berkeley.edu
Advisor Kristofer S.J. Pister

 
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Physical Sensors & Devices
Project IDBPN873 New Project
Project Title MEMS Filament Motors
Status New
Funding Source BSAC Member Fees
Keywords
Researchers Craig B. Schindler, Daniel S. Contreras, Joseph T. Greenspun
Abstract Pushup, walking, jumping, and flying microrobots have been demonstrated. Other previous work has demonstrated microelectromechanical systems (MEMS) capable of creating silicon silk, as well as microrobots capable of assembling millimeter scale carbon fibers. However, microrobots capable of manipulating very small diameter filaments, fibers, and wires initially external to themselves is still an area of open research. We have successfully demonstrated a silicon-on-insulator (SOI) MEMS device pushing a 7 um diameter carbon filament through an adjustable width channel at a speed of 0.2 mm/s. Future applications include a microrobotic spider, an array of individually controllable neural probe implanters, a wound or fabric stitching microrobot, plug-and-play linear servos for paper robots, etc.
Contact Information craig.schindler@berkeley.edu
Advisor Kristofer S.J. Pister

 
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Physical Sensors & Devices
Project IDBPN857
Project Title Miniature Autonomous Rockets
Status Continuing
Funding Source BSAC Member Fees
Keywords MEMS, Inchworm Motors, MAVs
Researchers Brian G. Kilberg, Daniel Contreras
Abstract While effective miniature scale rocket motors have been developed, viable control surfaces at that scale do not exist. The goal of this project is to develop the necessary control system and actuators to enable autonomous millimeter to centimeter scale rockets. The proposed rocket control surfaces consist of electrostatic inchworm motors and planar linkages that are fabricated on a silicon-on-insulator wafer. These actuators will be driven by high voltage buffers and will be controlled by an electronic system consisting of a CMOS SOC, an inertial measurement unit, and a CMOS camera. We have developed preliminary simulations for the mechanics and control of the rocket, and we have fabricated the control surface actuators. These actuators were able to produce 1.575 uNm of torque, which corresponds to an equivalent aerodynamic force of 1.4 mN. Currently, we are characterizing the aerodynamic performance of these control surfaces using an integrated silicon strain gauge. We plan to integrate the control surfaces into a small model rocket to demonstrate their functionality.
Contact Information bkilberg@berkeley.edu
Advisor Kristofer S.J. Pister

 
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Table of Projects
Wireless, RF & Smart Dust
Project IDBPN735
Project Title Walking Silicon Microrobots
Status Continuing
Funding Source BSAC Member Fees
Keywords Microrobotics, electrostatics, actuators, MEMS
Researchers Daniel Contreras
Abstract This project focuses on developing a new generation of sub-centimeter MEMS based walking robots. These robots are based on electrostatic actuators driving planar silicon linkages, all fabricated in the device layer of a silicon-on- insulator (SOI) wafer. By using electrostatic actuation, these legs have the advantage of being low power compared to other microrobot leg designs. This is key to granting the robot autonomy through low-power energy harvesting. The ultimate goal will be to join these silicon legs with a CMOS brain, battery power, a high voltage power source, and high voltage buffers to achieve a fully autonomous walking microrobot. Now that we have demonstrated locomotion of a single-legged walking robot through tethered external power, we are shifting our focus to developing a hexapod using a similar actuation scheme. The first generation silicon hexapod will be based on multi- chip assembly using silicon wafer throughole vias and demonstrate a basic dual tripod gait. We have also demonstrated electrostatic inchworm motors capable of actuating a shuttle at 35mm/s. We are also working on a new generation of motors with force generation over 2mN at 65V.
Contact Information dscontreras@eecs.berkeley.edu
Advisor Kristofer S.J. Pister

 
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Wireless, RF & Smart Dust
Project IDBPN858
Project Title Zero Insertion Force MEMS Socket for Microrobotics Assembly
Status Continuing
Funding Source Fellowship
Keywords mems, zif, microassembly, microrobot
Researchers Hani Gomez, Daniel Contreras, Joseph Greenspun
Abstract To help resolve the control and power challenges present in developing micro robots, the research focus of this project is the design and development of a ZIF (zero insertion force) MEMS (micro electro mechanical systems) socket. The ultimate goal is to achieve electrical connections between a 65nm single-chip mote and a multi-legged SOI micro robot. As proof of concept, the most recent socket prototype uses previous work on energy storage in springs to grip a MEMS motor chiplet. Both chiplets were fabricated using a two-mask SOI (silicon- on- insulator) process. The socket uses electrical probes to connect to pads on the motor chiplet, providing parallel electrical connection between the two chips. This design demonstrates mechanical connection, and the work also presents first results for the electrical contact resistances. Future work will allow MEMS structures to easily probe the pads of CMOS chips, strongly connecting the two technologies both electrically and mechanically (the connection is designed to withstand 1000s of g’s of vibration). The ZIF socket will provide a smooth and simple approach to the integration of CMOS chips with MEMS structures.
Contact Information gomezhc@berkeley.edu, dscontreras@berkeley.edu, greenspun@berkeley.edu, ksjp@berkeley.edu
Advisor Kristofer S.J. Pister

 
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Wireless, RF & Smart Dust
Project IDBPN744
Project Title Self-Destructing Silicon
Status Continuing
Funding Source DARPA
Keywords
Researchers Joseph Greenspun, Osama Khan, Travis Massey, Brad Wheeler, Ryan Shih
Abstract Funded under the DARPA Vanishing Programmable Resources (VaPR) program, this project explores the fundamental issues associated with making wireless sensor nodes disappear after achieving an objective. The MEMS Hammer is a micromachined device capable of storing mechanical energy and delivering that energy to a target. It has been used to fracture other microfabricated structures made of silicon and silicon dioxide. The MEMS Hammer is capable of storing a wide range of energies with the upper limit exceeding 10uJ. These devices have been characterized to determine the tradeoffs among energy stored, total stroke, and layout area. The MEMS Hammer is being developed for a variety of applications ranging from creating a self- destructing mote to creating jumping microrobots. A ratcheting system is being developed using electrostatic motors to create a fully automatic self-destruction system.
Contact Information ksjp@berkeley.edu, brad.wheeler@berkeley.edu, greenspun@eecs.berkeley.edu, oukhan@berkeley.edu, maha
Advisor Kristofer S.J. Pister, Michel M. Maharbiz

 
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Wireless, RF & Smart Dust
Project IDBPN803
Project Title Single Chip Mote
Status Continuing
Funding Source DARPA
Keywords
Researchers Osama Khan, David Burnett, Filip Maksimovic, Brad Wheeler
Abstract The Internet of Things (IoT) is a natural evolution of computing. CMOS technology enabled the network of computers that provided a platform for creating social networks. We are just seeing the early stages of another transition point in technology and entering into a new era where computing, sensing, and communication is essentially becoming disposable. The microsystem serves as a platform that allows us to embed wireless connectivity into everyday objects or serves as a brain for walking and flying microrobots. The lifetime, robustness, profile, and cost of these microsystems play a critical role to enable these emerging applications. Therefore, a single chip mote hardware platform is developed to address these unmet needs from the current existing hardware platforms. The system-on-chip (SoC) is architected from the bottom-up to meet the new use case and performance requirements of energy constrained environments with limited energy capacity e.g. batteryless operation from harvested energy or operation from printed batteries. The project seeks to reduce the active radio power by a factor of 10, reduce the overall system cost and profile of a microsystem by eliminating external components (e.g. crystal frequency reference) that are typically needed for a fully functioning wireless sensor node.
Contact Information oukhan@berkeley.edu, ksjp@berkeley.edu, brad.wheeler@berkeley.edu, db@eecs.berkeley.edu, fil@eecs.be
Advisor Kristofer S.J. Pister, Ali M. Niknejad

 
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Wireless, RF & Smart Dust
Project IDBPN859
Project Title UHF Channel-Selecting Bandpass Filter
Status Continuing
Funding Source Fellowship
Keywords Filter, resonator, 20nm, gaps, bandpass, frequency, ultra, high, UHF, banks
Researchers Alain Anton
Abstract This project aims to use micromechanical resonators with sub-20nm capacitive-transducer electrode- to-resonator gaps to realize banks of channel-selecting bandpass filters at UHF frequencies.
Contact Information aanto021@eecs.berkeley.edu
Advisor Clark T.-C. Nguyen

 
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Wireless, RF & Smart Dust
Project IDBPN828
Project Title Zero Quiescent Power Micromechanical Receiver
Status New
Funding Source DARPA
Keywords
Researchers Alper Ozgurluk, Ruonan Liu
Abstract This project aims to explore and demonstrate a mostly mechanical receiver capable of listening without consuming any power, consuming power only when receiving valid bits.
Contact Information ozgurluk@eecs.berkeley.edu, liur@eecs.berkeley.edu, ctnguyen@eecs.berkeley.edu
Advisor Clark T.-C. Nguyen

 
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Wireless, RF & Smart Dust
Project IDBPN814
Project Title UHF Capacitive-Gap Transduced Resonators With High Cx/Co
Status Continuing
Funding Source DARPA
Keywords
Researchers Alper Ozgurluk, Yafei Li
Abstract The project explores methods by which the Cx/Co of UHF capacitive-gap transduced resonators might be increased to above 5% while maintaining Q's >10,000.
Contact Information yafeili@berkeley.edu
Advisor Clark T.-C. Nguyen

 
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Wireless, RF & Smart Dust
Project IDBPN861
Project Title Fully Integrated MEMS-Based Super-Regenerative Transceiver
Status New
Funding Source DARPA
Keywords
Researchers Gleb Melnikov
Abstract This project aims to integrate our previously demonstrated MEMS-Based Super-Regenerative Transceiver in a fully integrated CMOS- MEMS fabrication process.
Contact Information gmelnikov@berkeley.edu
Advisor Clark T.-C. Nguyen

 
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Wireless, RF & Smart Dust
Project IDBPN701
Project Title Bridged Micromechanical Filters
Status Continuing
Funding Source DARPA
Keywords Micromechanical Filters, High-order Filters,
Researchers Jalal Naghsh Nilchi
Abstract The overall project aims to explore the use of bridging between non-adjacent resonators to generate loss poles in the filter response toward better filter shape factor, sharper passband- to-stopband roll-off and better stopband rejection.
Contact Information jalal.naghsh.nilchi@berkeley.edu
Advisor Clark T.-C. Nguyen

 
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NanoTechnology: Materials, Processes & Devices
Project IDBPN867
Project Title Fully Integrated CMOS-Metal MEMS Systems
Status Continuing
Funding Source DARPA
Keywords
Researchers Kieran A. Peleaux
Abstract This project aims to integrate metal MEMS resonators directly over CMOS to achieve fully integrated MEMS systems.
Contact Information kpeleaux@berkeley.edu, ctnguyen@berkeley.edu
Advisor Clark T.-C. Nguyen

 
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Wireless, RF & Smart Dust
Project IDBPN865
Project Title CMOS-Assisted Resoswitch Receivers
Status Continuing
Funding Source DARPA
Keywords
Researchers Kyle K. Tanghe
Abstract This project aims to harness extremely low power CMOS integrated circuits to boost the Q’s of micromechanical resoswitches towards much higher sensitivity resoswitch receivers.
Contact Information tanghek@berkeley.edu
Advisor Clark T.-C. Nguyen

 
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Wireless, RF & Smart Dust
Project IDBPN866
Project Title Wide-Bandwidth UHF Bandpass Filters
Status New
Funding Source DARPA
Keywords UHF, Wideband, Filter
Researchers Qianyi Xie
Abstract This project aims to use micromechanical resonators with sub-20nm capacitive-transducer electrode-to- resonator gaps to realize wide-bandwidth bandpass filters at UHF frequencies.
Contact Information qianyi_xie@berkeley.edu, ctnguyen@berkeley.edu
Advisor Clark T.-C. Nguyen

 
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Wireless, RF & Smart Dust
Project IDBPN864
Project Title Micromechanical Resonator Waveform Synthesizer
Status New
Funding Source DARPA
Keywords
Researchers Thanh-Phong Nguyen
Abstract This project aims to demonstrate a waveform synthesizer using multiple micromechanical resonator oscillators with outputs combined.
Contact Information thanhphong_nguyen@berkeley.edu
Advisor Clark T.-C. Nguyen

 
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Package, Process & Microassembly
Project IDBPN354
Project Title The Nanoshift Concept: Innovation through Design, Development, Prototyping and Fabrication of MEMS, Microfluidics, Nano- and Clean Technologies
Status Continuing
Funding Source Industry
Keywords Nanoshift, nanolab, microlab, process, recharge, commercial
Researchers Ning Chen, Salah Uddin
Abstract Nanoshift LLC is a privately held research and development company specializing in MEMS, microfluidics, and nanotechnologies. Nanoshift provides high quality, customizable services for device and process design, research and development, rapid prototyping, low-volume fabrication, and technology transfer into high volume. Projects are typically from industry, government, and academia. Nanoshift is the solution for your device concept-to- commercialization needs. Nanoshift collaborates with BSAC to make industry-leading development resources available for all BSAC Industrial Members, while improving BSAC's visibility and funding.
Contact Information reception@bsac.eecs.berkeley.edu
Advisor Michael D. Cable

 
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Micropower
Project IDBPN874 New Project
Project Title Charge Pumping with Finger Capacitance for Body Energy Harvesting
Status New
Funding Source Foundation
Keywords energy harvesting, charge pumping, electrostatic, body capacitance
Researchers Alyssa Y. Zhou
Abstract We propose a touch interrogation powered energy harvesting system which transforms the kinetic energy of a human finger to electric energy. As is well known for touch display devices, the proximity of a finger can alter the effective value of small capacitances. We utilize these capacitance changes through a harvesting circuit to charge a capacitor with each finger tap. This technology illustrates the ability to communicate with and operate low-power sensors with motions already used for interfacing to devices.
Contact Information alyssa.zhou@berkeley.edu, maharbiz@berkeley.edu
Advisor Michel M. Maharbiz

 
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BioMEMS
Project IDBPN718
Project Title Direct Electron-Mediated Control of Hybrid Multi-Cellular Robots
Status Continuing
Funding Source Office of Naval Research (ONR)
Keywords microbiorobotics, synthetic biology, biosensors, hybrid biological systems, bacterial electrophysiology
Researchers Alyssa Y. Zhou, Tom J. Zajdel
Abstract We propose a millimeter-scale, programmable cellular-synthetic hybrid sensor node capable of sensing and response in aqueous environments. This will be the first demonstration of a millimeter-scale synthetic autonomous multi-cellular hybrid with organic and man-made components. We have successfully developed a miniaturized bioelectronic sensing system (BESSY) including a centimeter-scale, two-channel, three-electrode potentiostat and a custom-fabricated, submersible, self-contained miniaturized reactor (m-reactor). The BESSY is capable of in-situ sensing of specific chemicals among environmental perturbations using differential current measurement.
Contact Information alyssa.zhou@berkeley.edu, zajdel@eecs.berkeley.edu, maharbiz@berkeley.edu
Advisor Michel M. Maharbiz

 
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BioMEMS
Project IDBPN853
Project Title Tethered Bacteria-Based Biosensing
Status Continuing
Funding Source Office of Naval Research (ONR)
Keywords biosensing, bacterial chemotaxis, bacterial flagellar motor, microbiorobotics
Researchers Tom J. Zajdel
Abstract Though the chemotaxis sensing system of emph{Escherichia coli} is known to approach fundamental physical limits for biosensing, few attempts have been made to co-opt the system as the front end for a biohybrid sensor. We propose a biohybrid sensor that monitors chemotactic bacterial flagellar motor (BFM) rotation speed and direction to infer analyte concentration for a low-power, fast, and sensitive response. We present the design and fabrication of a four point impedimetric array that uses current injection electrodes to circumvent electrode polarization screening, enabling solution resistance monitoring within a four-micron by four-micron region. We also demonstrate the first lithographically patterned silica shaft encoders for the BFM, which utilize localized biotin-avidin chemistry to selectively bind to the BFM and encode rotation. When these two components are integrated by bringing the rotating shaft encoders in proximity to the microelectrode array, they will enable an electrochemical method for observing the BFM. Such an impedance-based biohybrid sensor obviates the need for a microscope and in principle may be multiplexed and scaled to large arrays of BFMs, enabling the development of deployable low-power and fast sensing systems that directly observe the BFM to infer analyte concentration.
Contact Information zajdel@eecs.berkeley.edu, maharbiz@berkeley.edu
Advisor Michel M. Maharbiz

 
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Physical Sensors & Devices
Project IDBPN765
Project Title Full-Field Strain Sensor for Hernia Mesh Repairs
Status Continuing
Funding Source NSF
Keywords strain
Researchers Amy Liao
Abstract Each year, more than 400,000 ventral hernia repairs are performed in the United States. A hernia is the protrusion of an organ through a weak spot in the surrounding muscle or connective tissue that normal contains it. Large ventral hernias (hernias that occur in the abdominal wall) are typically treated by suturing in a surgical mesh to cover and overlap the hernia defect. The surgical mesh provides additional support to the damaged tissue surrounding the hernia. However, in 25-40% of patients, the hernia repair fails, resulting in recurrence of the hernia, along with other complications including infection and intestinal obstruction. We hypothesize that a major cause of hernia recurrence is the unequal distribution of stress across the mesh resulting in high stress concentrations at the tissue-mesh interface, particularly at the site of mesh fixation to the abdominal wall muscles. Over time the mesh is pulled away from the abdominal wall at the high stress concentrations and the hernia defect recurs. We propose to design a biocompatible, instrumented patch, capable of mapping the 2D strain topography placed on the mesh. The sensor will enable surgeons to actively identify and address areas of high stress during the surgery by modifying the surgical procedure to redistribute stress more evenly, thus decreasing the rate of hernia recurrence. Furthermore, our long term goal is to design a hernia mesh that contains strain sensors that once implanted in the body the prosthetic can noninvasively alert patients when they are engaging in activities that place high stress on the implant. Such a dynamic, interactive hernia mesh would empower patients to actively participate in their post-operative care in a way that is personalized and unprecedented in surgery.
Contact Information amy.liao@berkeley.edu
Advisor Michel M. Maharbiz

 
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Physical Sensors & Devices
Project IDBPN714
Project Title Impedance Sensing Device to Monitor Pressure Ulcers
Status Continuing
Funding Source NSF
Keywords Wound Healing, Impedance Spectroscopy
Researchers Amy Liao, Monica C. Lin
Abstract Chronic cutaneous wounds affect millions of people each year and take billions of dollars to treat. Formation of pressure ulcers is considered a "never event" - an inexcusable, adverse event that occurs in a healthcare setting. Current monitoring solutions (pressure-distributing beds, repositioning patients every few hours, etc) are very expensive and labor intensive. In response to this challenge, we are developing a novel, flexible monitoring device that utilizes impedance spectroscopy to measure and characterize tissue health, thus allowing physicians to objectively monitor progression of wound healing as well as to identify high-risk areas of skin to prevent formation of pressure ulcers. Previous studies that examined the dielectric response of cell suspensions and tissues have identified several distinct dispersions associated with particular molecular-level processes that can be used to distinguish between tissue types. We are utilizing impedance spectroscopy to detect subtle changes in tissue, enabling objective assessment and providing a unique insight into the condition of a wound. Wireless capability can be implemented to allow for continuous, remote monitoring.
Contact Information amy.liao@berkeley.edu, monica.lin@berkeley.edu
Advisor Michel M. Maharbiz

 
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Physical Sensors & Devices
Project IDBPN780
Project Title Impedance Spectroscopy to Monitor Fracture Healing
Status Continuing
Funding Source NSF
Keywords
Researchers Monica C. Lin
Abstract An estimated 15 million fracture injuries occur each year in the United States. Of these, 10% of fractures result in delayed or non-union, with this number rising to 46% when they occur in conjunction with vascular injury. Current methods of monitoring include taking X-rays and making clinical observations. However, radiographic techniques lag and physician examination of injury is fraught with subjectivity. No standardized methods exist to assess the extent of healing that has taken place in a fracture, revealing the need for a diagnostic device that can reliably detect non-union in its early pathologic phases. Electrical impedance spectroscopy has been used to characterize different tissues, and we hypothesize that this technique can be applied to fractures to distinguish between the various types of tissue present in the clearly defined stages of healing. We are developing an objective measurement tool that utilizes impedance spectroscopy to monitor fracture healing, with the goal of providing physicians with more information that can resolve the initial stages of fracture healing. This would enable early intervention to prevent problem fractures from progressing to non-union.
Contact Information monica.lin@berkeley.edu
Advisor Michel M. Maharbiz

 
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Wireless, RF & Smart Dust
Project IDBPN844
Project Title Wireless Sub-Millimeter Temperature Sensor for Continuous Temperature Monitoring in Tissue
Status Continuing
Funding Source DARPA
Keywords Sensor, wireless, monitoring, biomedical, chronic, implant, temperature, thermometer, ultrasound, backscatter
Researchers B. Arda Ozilgen
Abstract We demonstrate a tetherless, sub-millimeter implantable temperature sensing system employing ultrasonic powering and ultrasonic backscatter modulation assembled using commercially available components. We have demonstrated two sizes of sensors based on available components with volumes of 1.45 mm3 and 0.118 mm3. Individual sensors are able to resolve ±0.5 °C changes in temperature, suitable for medical diagnostic and monitoring purposes. We have demonstrated less than 0.3 °C drift in temperature readings over 14 days in physiological temperature conditions. Our goal is to solve a long-standing issue: chronically and tetherlessly monitoring deep tissue temperature.
Contact Information arda.ozilgen@berkeley.edu
Advisor Michel M. Maharbiz

 
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BioMEMS
Project IDBPN816
Project Title Cytokine Fast Detection
Status Continuing
Funding Source DARPA
Keywords Ion concentration polarization, ultrafast enrichment
Researchers Bochao Lu
Abstract Sepsis is a life-threatening condition both in civilian and military medical scenarios. Patients with sepsis usually exhibit a vigorous systemic release of cytokines such as interleukin-1 (IL-1), interleukin-6 (IL-6) and tumor necrosis factor (TNF) into serum. The ability to monitor relative cytokine levels continuously at fast time scales (tens of minutes) could open the door to closed-loop, patient-specific sepsis management therapies. The current methods of cytokine detection take hours and cost thousands of dollars because the physiological concentration is so low around femtomolar. At such low concentrations, the limiting factor becomes mass transport instead of binding kinetics, due to increased diffusion length from bulk solution to sensor surface. We present a method, based on nanofabrication and ion concentration polarization (ICP) which enriches analytes using only a DC power supply.
Contact Information steven_lu@berkeley.edu
Advisor Michel M. Maharbiz

 
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BioMEMS
Project IDBPN716
Project Title Ultrasonic Wireless Implants for Neuro-Modulation
Status Continuing
Funding Source DARPA
Keywords brain-machine interfaces, ultrasonic energy transfer and harvesting, backscatter communication
Researchers Konlin Shen, David Piech, B. Arda Ozilgen
Abstract A major hurdle in brain-machine interfaces (BMI) is the lack of an implantable neural interface system that remains viable for a substantial fraction of a primate lifetime. Recently, sub-mm implantable, wireless electromagnetic (EM) neural interfaces have been demonstrated in an effort to extend system longevity. However, EM systems do not scale down in size well due to the severe inefficiency of coupling radio waves at mm and sub-mm scales. We propose an alternative wireless power and data telemetry scheme using distributed, ultrasonic backscattering systems to record high frequency (~kHz) neural activity. Such systems will require two fundamental technology innovations: 1) thousands of 10 – 100 um scale, free- floating, independent sensor nodes, or neural dust, that detect and report local extracellular electrophysiological data via ultrasonic backscattering, and 2) a sub-cranial ultrasonic interrogator that establishes power and communication links with the neural dust. To test the feasibility of this approach, we performed the first in-vivo experiments in the rat model, where we were able to recover mV-level action potential signals from the peripheral nerves. Further miniaturization of implantable interface based on ultrasound would pave the way for both truly chronic BMI and massive scaling in the number of neural recordings from the nervous system.
Contact Information konlin@berkeley.edu, piech@berkeley.edu, arda.ozilgen@berkeley.edu, maharbiz@berkeley.edu
Advisor Michel M. Maharbiz

 
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BioMEMS
Project IDBPN795
Project Title An Implantable Micro-Sensor for Cancer Surveillance
Status Continuing
Funding Source BSAC Member Fees
Keywords prostate cancer, beta radiation, Solid-state detectors, Low noise, CMOS, Imaging
Researchers Stefanie V. Garcia, Kyoungtae Lee
Abstract We aim to develop a micro surveillance device for early identification of cancerous cell growth in collaboration with radiation oncology research from UCSF. UCSF will develop a molecular probe that specifically targets prostate specific membrane antigen (PSMA), which is over-expressed on prostate cancer cells. By radiolabelling these probes, cancer sites may be monitored in conjunction with an implantable array. We will design a 100x100 um semiconductor radiation sensor that can feasibly detect and localize cancer recurrence from 10^4 – 10^5 cells when placed near a cancer site. The sensors will use ultrasonic methods for power and signal transmission, as demonstrated in Dongjin et al, arXiv preprint arXiV:1307.2196 (2013). Initial sensor design will enhance CMOS device sensitivity to time dependent signal variation and will also explore signal recovery in the limited biological window where the radiolabelled probe is detectable.
Contact Information stefanievgarcia@berkeley.edu
Advisor Michel M. Maharbiz

 
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Wireless, RF & Smart Dust
Project IDBPN848
Project Title Highly Integrated, Compact Wearable Ultrasound System for Chronic Biosensing
Status Continuing
Funding Source DARPA
Keywords ultrasound, low-power, wearable, biosensing, neural dust
Researchers David Piech, Josh Kay
Abstract Recent advances in low-power ultrasonics have enabled highly integrated, compact ultrasound systems. In addition, new ultrasonic biosensing modalities for chronic sensing native of tissue or communicating with implanted sensor nodes motivate the need for a wearable ultrasound system. Here, we integrate a low-power, high-voltage transducer driver (Tang, 2015), into a highly compact wearable device designed to unobtrusively provide continuous ultrasound monitoring of subject biometrics. We demonstrate its capability by interfacing with one type of ultrasonic backscatter dust mote, the Neural Dust mote (Seo, 2016).
Contact Information piech@berkeley.edu, j_kay@berkeley.edu
Advisor Michel M. Maharbiz, Bernhard E. Boser

 
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BioMEMS
Project IDBPN573
Project Title Fabrication and Microassembly of a High-Density Carbon Fiber Neural Recording Array
Status Continuing
Funding Source DARPA
Keywords carbon fiber microelectrode electrode array electrophysiology chronic stimulation recording high density
Researchers Travis L. Massey, Jason F. Hou
Abstract We present a 32-channel carbon fiber monofilament-based intracortical neural recording array fabricated through a combination of bulk silicon microfabrication processing and microassembly. This device represents the first truly two-dimensional carbon fiber neural recording array. The five-micron diameter fibers are spaced at a pitch of 38 microns, four times denser than the state of the art one-dimensional arrays. The fine diameter of the carbon fiber microwires affords both minimal cross-section and nearly three orders of magnitude greater lateral compliance than standard tungsten microwires. Both of these serve to minimize the adverse biological response to implanted devices, particularly compared to conventional implantable microelectrodes. The electrode pitch, in turn, has the potential to enable localization of individual units by detection at multiple adjacent sites, something traditionally the domain of polytrodes. The density, channel count, and size scale of this array are enabled by a microfabricated silicon substrate and a out-of-plane microassembly technique in which individual fibers are inserted through metallized and isotropically conductive adhesive-filled holes in the oxide-passivated silicon substrate. Insertion is eased and the fibers aligned to within five milliradians using an array of microfabricated funnels. The device is insulated in parylene for biocompatibility and electrical isolation, and the recording sites are electroplated with PEDOT:PSS to an impedance on the order of tens of kiloohms at 1 kHz. Further, this fabrication technique is scalable to a larger number of electrodes and allows for the potential future integration of microelectronics.
Contact Information tlmassey@eecs.berkeley.edu
Advisor Michel M. Maharbiz, Kristofer S.J. Pister

 
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Wireless, RF & Smart Dust
Project IDBPN871 New Project
Project Title An Ultrasonic Implantable for Continuous In Vivo Monitoring of Tissue Oxygenation
Status New
Funding Source Foundation
Keywords
Researchers Soner Sonmezoglu
Abstract Our group previously demonstrated a “neural dust” system for neural recording which includes an implantable device and external ultrasonic transducers to power and communicate with the implantable. In this work, we extend that paradigm, demonstrating an implantable that can measure and report tissue oxygenation. Oxygenation state is a key parameter when assessing the metabolic state of cells and tissues, tissue and organ viability, tumor state, among many examples in both basic science and clinical care. Various types of methods for the detection of oxygen have appeared in recent years, including the Clark electrode, Winkler titration, and optical sensing. Among these, there is a growing interest in optical sensors for use in consumer electronic devices because they possess advantages of (a) fast response, (b) high sensitivity, (c) good precision and accuracy, (d) lack of oxygen consumption during measurements, (e) ease of miniaturization, (f) low cost, and (g) enabling in vivo, non-invasive and real- time measurements. In this project, we aim to develop a miniaturized oxygen sensor system consisting of a micro-light emitting diodes (LEDs) for optical excitation, bio- compatible thin-film for encapsulation of an oxygen-sensitive fluorophore, ultrasonic transducer for wireless communication and wireless powering of the implantable device, and single-chip CMOS integrated circuit for optical detection and signal processing. The sensor system determines oxygen level utilizing the fluorescence lifetime of a fluorophore, which is a function of the oxygen concentration of the thin film that is influenced by the surrounding environment.
Contact Information ssonmezoglu@berkeley.edu
Advisor Michel M. Maharbiz, Mekhail Anwar

 
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BioMEMS
Project IDBPN884 New Project
Project Title Anisotropic Proton Transport in Artificially Aligned Collagen Fiber
Status New
Funding Source Foundation
Keywords anisotropic proton transport, nematic
Researchers Doyeon Bang
Abstract Proton transportation is ubiquitous in biological signaling as well as enabled a broad range of modern device components. However, proton conductor using tunable, controllable and mass producible biological material is not yet developed for in vivo application to interface biological system. Here, we demonstrate anisotropic proton transport in the artificially aligned collagen fiber network, which is mimicking the nematic structure of the muscle fiber to show that aligned collagen can assist biological signaling as a protonic highway. Artificially aligned nematic collagen fiber network is synthesized by “grow-and-snap” method, which produces >94.2% of collagen fiber is aligned along the fluid streamline (± 10º), and >82.3% of collagen fibril is aligned along the direction of the fiber (± 10º). We demonstrate that proton conduction in nematic collagen network is Grotthuss hopping along the backbone of tropocollagen chain according to the measurement of the activation energy of the proton transportation (~ 0.19 eV) and proton conduction along the tropocollagen chain result in the surface-charge mediated two-dimensional transport, which is generally observed in the nanofluidic channels. According to the fiber orientation dependent proton conduction measurement, anisotropic proton transportation is found due to the structural anisotropy and horizontally aligned collagen fiber network exhibited higher conductance over vertically aligned collagen fiber. The understanding of the mechanism of collagen assistance to proton transport may build up a theoretical basis for further development of therapy method to cure wound-induced proton-transfer disability.
Contact Information doyeonbang@berkeley.edu
Advisor Luke P. Lee

 
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BioMEMS
Project IDBPN829
Project Title Integrated Multiplexed Optical Microfluidic System (iMOMs) for Dengue Diagnosis
Status Continuing
Funding Source Fellowship
Keywords Diagnostics, Dengue, qPCR, immunoassay, multiplexed detection
Researchers Jong-Hwan Lee, Jun Ho Son
Abstract Dengue is an endemic viral disease that affects tropical and subtropical areas. It is estimated that more than 50 million infections occur worldwide per year. Due to its lack of pathognomonic clinical features, dengue is often mistakenly diagnosed as other febrile diseases, which thus leads to ineffective and costly overtreatment. Previously developed diagnostic tests for dengue can only detect a single biomarker (or two to three kinds of targets) at a time and they also lack comprehensive and syntagmatic analysis between various dengue-specific biomarkers. For an effective and precision diagnostics of dengue infection, a diagnostic test should not only be highly sensitive and specific, but also determine dengue virus serotype and distinguish between primary and secondary infection. This can only be accomplished by developing a multiplexed test that covers multiple targets. Here we present an integrated multiplexed optical microfluidic system (iMOMs) with the detection capability of four different nucleic acids biomarkers and five different protein biomarkers (i.e. NS-1, IgM, IgG, IgA, and IgE) on chip. We design, simulate, and fabricate the iMOMs using polymer microfluidic substrates. We integrate biological printing technology with the microfluidic device technology. We demonstrate multiplexed dengue specific- nucleic acid amplifications and immunoassays. The iMOMs will be an ideal dengue diagnostic platform for both developed and developing countries and can be applied to give accurate and ultra-sensitive point-of- care diagnoses for other intractable diseases as well.
Contact Information jonghwanlee@berkeley.edu
Advisor Luke P. Lee

 
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NanoPlasmonics, Microphotonics & Imaging
Project IDBPN809
Project Title Photonic Cavity Bioreactor for High-throughput Screening of Microalgae
Status Continuing
Funding Source Foundation
Keywords biofuel, microalgae, bioenergy, bioreactor, high-throughput screening, photonic cavity
Researchers Minsun Song, SoonGweon Hong
Abstract Algal photosynthesis is considered to be a sustainable, alternative and renewable solution to generating green energy. For high-productivity algaculture in diverse local environments, a high-throughput screening method is needed in selecting algal strains from naturally available or genetically engineered strains. Herein, we present an integrated plasmonic photobioreactor for rapid, high-throughput screening of microalgae. Our 3D nanoplasmonic optical cavity-based photobioreactor permits the amplification of selective wavelength favorable to photosynthesis in the cavity. The hemispheric plasmonic cavity allows to promote intercellular interaction in the optically favorable milieu and also permits effective visual examination of algal growth. Using Chlamydomonas reinhardtii, we demonstrated 2 times of enhanced growth rate and 1.5 times of lipid production rate with no distinctive lag phase. By facilitating growth and biomass conversion rates, the integrated microalga analysis platform (iMAP) will serve as rapid microalgae screening platforms for biofuel applications.
Contact Information sms1115@berkeley.edu
Advisor Luke P. Lee

 
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NanoTechnology: Materials, Processes & Devices
Project IDBPN881 New Project
Project Title Strain-engineered growth of two-dimensional materials
Status New
Funding Source Federal
Keywords
Researchers Geun Ho Ahn, Matin Amani
Abstract The application of strain to semiconductors allows for controlled modification of their band- structure. This principle is employed for the manufacturing of devices ranging from high-performance transistors to solid-state lasers. Traditionally, strain is typically achieved via growth on lattice- mismatched substrates. For two-dimensional (2D) semiconductors, this is not feasible as they typically do not interact epitaxially with the substrate. Here, we demonstrate controlled strain engineering of 2D semiconductors during synthesis by utilizing the thermal coefficient of expansion (TCE) mismatch between the substrate and semiconductor. Using WSe2 as a model system, we demonstrate stable built-in strains ranging from 1% tensile to 0.2% compressive on substrates with different TCE. Consequently, we observe dramatic modulation of the band-structure, manifested by a strain-driven indirect-to-direct bandgap transition and brightening of the dark exciton in bilayer and monolayer WSe2, respectively. The growth method developed here should enable flexibility in design of more sophisticated devices based on 2D materials.
Contact Information gnoahn.int@berkeley.edu
Advisor Ali Javey

 
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Physical Sensors & Devices
Project IDBPN818
Project Title Fully-Integrated Wearable Sensor Arrays for Multiplexed In Situ Perspiration Analysis
Status Continuing
Funding Source BSAC Member Fees
Keywords Sweat, biosensors, system integration, wearable devices, flexible electronics
Researchers Hnin Y.Y. Nyein, Wei Gao, Mallika Bariya
Abstract A flexible and wearable microsensor array is described for simultaneous multiplexed monitoring of heavy metals in human body fluids. Zn, Cd, Pb, Cu, and Hg ions are chosen as target analytes for detection via electrochemical square wave anodic stripping voltammetry (SWASV) on Au and Bi microelectrodes. The oxidation peaks of these metals are calibrated and compensated by incorporating a skin temperature sensor. High selectivity, repeatability, and flexibility of the sensor arrays are presented. Human sweat and urine samples are collected for heavy metal analysis, and measured results from the microsensors are validated through inductively coupled plasma mass spectrometry (ICP-MS). Real-time on-body evaluation of heavy metal (e.g., zinc and copper) levels in sweat of human subjects by cycling is performed to examine the change in concentrations with time. This platform is anticipated to provide insightful information about an individual’s health state such as heavy metal exposure and aid the related clinical investigations.
Contact Information hnyein@berkeley.edu
Advisor Ali Javey

 
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Physical Sensors & Devices
Project IDBPN770
Project Title Chemical Sensitive Field Effect Transistor (CS-FET)
Status Continuing
Funding Source NSF
Keywords CS-FET, Gas Sensor, microfabrication, TMO
Researchers Hossain M. Fahad
Abstract Silicon IC-based fabrication processing will be used to develop novel compact gas sensors that, unlike current sensors, will operate at room temperature, consume minimal power, exhibit superior sensitivity, provide chemical selectivity and multi-gas detection capabilities, and offer the prospect of very low-cost replication for broad-area deployment. We name this device structure “Chemical Sensitive FET” or “CS-FET.” The operation of the CS-FET involves transistor parametric differentiation under influence of differentiated gas exposures.
Contact Information hossain.fahad@berkeley.edu
Advisor Ali Javey

 
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Physical Sensors & Devices
Project IDBPN883 New Project
Project Title Microchannel contacting of crystalline silicon solar cells
Status New
Funding Source Federal
Keywords Solar cells, Microchannels
Researchers James Bullock, Mark Hettick
Abstract There is tremendous interest in reducing losses caused by the metal contacts in silicon photovoltaics, particularly the optical and resistive losses of the front metal grid. One commonly sought after goal is the creation of high aspect-ratio metal fingers which provide an optically narrow and low resistance pathway to the external circuit. Currently, the most widely used metal contact deposition techniques are limited to widths and aspect-ratios of ~40 μm and ~0.5, respectively. In this study, we introduce the use of a micropatterned polydimethylsiloxane encapsulation layer to form narrow (~20 μm) microchannels, with aspect-ratios up to 8, on the surface of solar cells. We demonstrate that low temperature metal pastes, electroless plating and atomic layer deposition can all be used within the microchannels. Further, we fabricate proof-of- concept structures including simple planar silicon heterojunction and homojunction solar cells. While preliminary in both design and efficiency, these results demonstrate the potential of this approach and its compatibility with current solar cell architectures.
Contact Information james.bullock@berkeley.edu
Advisor Ali Javey

 
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NanoTechnology: Materials, Processes & Devices
Project IDBPN704
Project Title Vapor-Liquid-Solid Growth of Polycrystalline Indium Phosphide Thin Films on Metal
Status Continuing
Funding Source Federal
Keywords Solar Cells, Photovoltaics, Indium Phosphide, InP, VLS, Thin Film
Researchers Mark Hettick
Abstract Here, we develop a technique that enables direct growth of III-V materials on non- epitaxial substrates. Here, by utilizing a planar liquid phase template, we extend the VLS growth mode to enable polycrystalline indium phosphide (InP) thin film growth on Mo foils.
Contact Information mark.hettick@berkeley.edu
Advisor Ali Javey

 
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Physical Sensors & Devices
Project IDBPN879 New Project
Project Title A wearable impedance-based microfluidic sensor for sweat rate monitoring
Status New
Funding Source BSAC Member Fees
Keywords
Researchers Li-Chia Tai
Abstract A flexible and wearable sensor is presented for real-time monitoring of localized perspiration rate of human subjects. These sweat rate measurements are validated through controlled syringe pumping and a commercial sweat collector. Real- time on-body perspiration rate evaluation of human subjects is performed through cycling experiments to examine the change in sweat rate with different power output. Since it has been shown that the concentrations of a large number of sweat biomarkers are strongly related to the variation of a subject’s perspiration rate, this platform is anticipated to facilitate an accurate analysis of sweat biomarkers and provide insightful information regarding an individual’s health state.
Contact Information j.tai@berkeley.edu
Advisor Ali Javey

 
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NanoTechnology: Materials, Processes & Devices
Project IDBPN822
Project Title Monolayer Semiconductor Optoelectronics
Status Continuing
Funding Source Federal
Keywords
Researchers Matin Amani, Der-Hsien Lien
Abstract While two dimensional (2D) semiconductors show great promise for optoelectronic applications, due to a myriad of highly attractive properties which cannot be readily achieved in traditional III-V systems, to date they have shown tremendously poor photoluminescence quantum yield (QY). High QY is a requirement for materials used in key optoelectronic devices such as LEDs, lasers, and solar cells, since it determines the efficiency of light emission. Traditional three-dimensional materials like GaAs require lattice matched cladding layers to obtain high QY, on the other hand 2D materials which have naturally terminated surfaces should be able to exhibit near-unity QY provided that there are no defects in the crystal. To this end, we have recently demonstrated that through chemical treatments with an organic superacid the defect sites on the surface of MoS2, the prototypical 2D material, can be passivated. Solution based treatment of defects is especially effective in monolayer semiconductors since the entire "bulk" of the semiconductor is also the surface. As a result, the QY can be enhanced from less than 1% to over 95% in micromechanically exfoliated MoS2. In this project we seek to expand this treatment to other 2D material systems and 2D materials grown by chemical vapor deposition, as well as realize light emitting devices based on perfect optoelectronic monolayers.
Contact Information mamani@berkeley.edu, ajavey@berkeley.edu
Advisor Ali Javey

 
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NanoTechnology: Materials, Processes & Devices
Project IDBPN862
Project Title MoS2 Transistors with 1-Nanometer Gate Lengths
Status Continuing
Funding Source Federal
Keywords MoS2, 1-nanometer gate, TMDC, scaling
Researchers Sujay B. Desai
Abstract MoS2 transistors with a 1-nm physical gate length using a single-walled carbon nanotube as the gate electrode are demonstrated. These ultrashort devices exhibit excellent switching characteristics with near ideal subthreshold swing ~65 millivolts per decade and an On/Off current ratio ~10^6. Simulations show an effective channel length of ~3.9 nm in the Off-state and ~1 nm in the On-state. The work here provides new insight into the ultimate scaling of gate lengths for a FET by surpassing the 5 nm limit often associated with Si technology. Future work involves improving the performance of these transistors and investigating the properties of other materials like Si at short gate-lengths.
Contact Information sujaydesai@eecs.berkeley.edu
Advisor Ali Javey

 
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Physical Sensors & Devices
Project IDBPN608
Project Title FM Gyroscope
Status Continuing
Funding Source DARPA
Keywords gyroscope, fm gyroscope, scale factor, bias stability, calibration
Researchers Burak Eminoglu, Kaveh Gharehbaghi
Abstract MEMS gyroscopes for consumer devices, such as smartphones and tablets, suffer from high power consumption and drift which precludes their use in inertial navigation applications. Conventional MEMS gyroscopes detect Coriolis force through measurement of very small displacements on a sense axis, which requires low-noise, and consequently high-power, electronics. The sensitivity of the gyroscope is improved through mode-matching, but this introduces many other problems, such as low bandwidth and unreliable scale factor. Additionally, the conventional Coriolis force detection method is very sensitive to asymmetries in the mechanical transducer because the rate signal is derived from only the sense axis. Parasitic coupling between the drive and sense axis introduces unwanted bias errors which could be rejected by a perfectly symmetric readout scheme. This project develops frequency modulated (FM) gyroscopes that overcome the above limitations. FM gyroscopes also promise to improve the power dissipation and drift of MEMS gyroscopes. We present results from a prototype FM gyroscope with integrated CMOS readout electronics demonstrating the principle.         
Contact Information eminoglu@eecs.berkeley.edu
Advisor Bernhard E. Boser

 
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Physical Sensors & Devices
Project IDBPN852
Project Title Frequency to Digital Converter for FM Gyroscopes
Status Continuing
Funding Source DARPA
Keywords Frequency to Digital Converters, FM Gyroscope
Researchers Kaveh Gharehbaghi, Burak Eminoglu
Abstract Frequency modulated (FM) gyroscopes are a new class of inertial sensors which measure the angular rotation rate. They offer several advantages including accurate scale factor, large dynamic range, and robust performance over temperature variation. The frequency of the output signal should be detected precisely to extract the slight frequency variations in modulated signal. This research focuses on the design of high-resolution frequency to digital converters (FDC) as an interface for FM gyroscopes. The key specifications which should be optimized are noise, dynamic range, and power consumption. The design procedure can be outlined as circuit level verification and system level optimization.
Contact Information kaveh@berkeley.edu
Advisor Bernhard E. Boser

 
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BioMEMS
Project IDBPN685
Project Title Real-Time Intraoperative Fluorescence Imager for Microscopic Residual Tumor in Breast Cancer
Status Continuing
Funding Source ASCO, DoD, and Mary Kay Foundation
Keywords cancer, fluorescence imaging, radiation, surgery, breast cancer, oncology
Researchers Efthymios P. Papageorgiou
Abstract Successful treatment of early stage cancer depends on the ability to resect both gross and microscopic disease, yet no method exists to identify residual cancer cells intraoperatively. This is particularly problematic in breast cancer, where microscopic residual disease can double the rate of cancer returning, from 15% to 30% over 15 years, affecting a striking 37,500 women annually. Currently, residual disease can only be identified by examining excised tumor under a microscope, visualizing tumor cells stained with specific tumor markers. This microscopic evaluation restricts identification of tumor cells to the post-operative setting. Unfortunately, traditional optics cannot be scaled to the sub-centimeter size necessary to fit into the cavity and be readily manipulated over the entire surface area. To solve this problem, we have developed an imaging strategy that forgoes external optical elements for focusing light and instead uses angle-selective gratings patterned in the metal interconnect of a standard CMOS process.
Contact Information epp@berkeley.edu
Advisor Bernhard E. Boser, Mekhail Anwar

 
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BioMEMS
Project IDBPN882 New Project
Project Title An Ultra-Thin Molecular Imaging Skin for Intraoperative Cancer Detection Using Time-Resolved CMOS Sensors
Status New
Funding Source ASCO, DoD, and Mary Kay Foundation
Keywords
Researchers Hossein Najafiaghdam
Abstract Successful treatment of cancer requires targeted and individualized treatment, and subsequently an assessment of the state of the tumor being examined, both gross and microscopic, however oncologists have no method of identifying microscopic tumor in the patient.  This results in tumor cells being left behind in patients undergoing surgery. Currently, the only way to determine the presence of any microscopic residual is to examine the excised tumor, stained with a proper marker, under a microscope, which only adds to the complexity and length of the surgery and treatment. The two current alternatives in these cases  are either to do a more expanded resection, causing more healthy cells to be removed as well in the process, or to simply estimate the residual disease to be negligible and risk a recurrence of the cancer. The modern biomarkers and staining of the cancer cells are sufficiently reliable to be detectable, nevertheless, they still need bulky focusing optics and high performance optical filters and as a result incompatible with the minimally invasive oncologic procedures of imaging small tumor cavities in surgical operations. Our solution brings the tools of pathology into the operation room (OR) and the tumor itself allowing to visualize and examine the tumor bed in real-time and alleviating the need for further operations in the future. This work takes advantage of the unique feature of the biomarker being used, enabling them to be excited at near- infrared (NIR) wavelengths and thanks to Silicon’s optical features, we can leverage its optical properties in the NIR range with a time-gated approach, to eliminate the need for optical equipment during the imaging process. As a result, we can almost effortlessly provide real-time information on the presence of potential residual disease in the patient during surgery and provide a direct visualization of microscopic tumor residuals in the patient to allow for a guided resection and a targeted treatment.
Contact Information hossein_najafi@berkeley.edu
Advisor Bernhard E. Boser, Mekhail Anwar

 
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NanoTechnology: Materials, Processes & Devices
Project IDBPN875 New Project
Project Title Transfer-Free Synthesis of Graphene on Insulating Substrates
Status New
Funding Source Industry
Keywords graphene, synthesis, CVD
Researchers Leslie L. Chan, Dung-Sheng Tsai
Abstract Graphene has become one of the pinnacles of nanomaterials research, touted for its manifold applications and potential as “the next silicon” in electronics. At this time, integrated production of graphene-based devices remains a barrier, requiring a process that is reliable, large-scale, and compatible with conventional fabrication approaches. One common method for graphene synthesis is chemical vapor deposition (CVD) on metal substrates, which requires a transfer step to target materials (e.g., insulating substrates for device applications). However, this extra transfer step often leads to wrinkles, contamination, and breakage that can lead to poor device performance. This project seeks to devise a robust method for growing high-quality, wafer-scale, mono/bi-layer graphene directly on insulating substrates such as SiO2, enabling efficient and coherent incorporation of graphene for next-generation devices.
Contact Information leslie.chan@berkeley.edu
Advisor Roya Maboudian

 
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NanoPlasmonics, Microphotonics & Imaging
Project IDBPN878 New Project
Project Title Super-resolution synthesis of nontrivial heterogeneous nanoparticles assisted by surface plasmons
Status New
Funding Source Fellowship
Keywords plasmonic, superresolution, colloidal chemistry
Researchers Arthur O. Montazeri
Abstract Project title: Super-resolution synthesis of nontrivial heterogeneous nanoparticles assisted by surface plasmons
Abstract: Colloidally produced nanoparticles are emerging as a solution for a variety of applications such as quantum dots, sensing, and functionalized targeted cell therapy. However, the thermodynamically driven process of their fabrication poses several constraints on their size and geometry, the most prominent being the high degree of symmetry in their shape. However, if energy (or matter) could be channeled with super-resolution, more complex architectures would become possible, such as partial cladding of complex nanoparticles with nontrivial shapes. This project explores alternative means of channeling energy into the nanoscale while the colloidal processing chemistry is taking place. We exploit the plasmonic activity of the particle itself to help channel light into a nonuniform heatmap over the particle with sub-particle resolution. We show that surface plasmons which result from the coupling of light with the free electrons in a metal, can be harnessed to achieve a variety of pre-programmed designer core-vest nanostructures. By localizing the energy carried by far-field radiation onto nanometer-sized regions, SPs effectively create hot blueprints that drive self-assembly of composite structures. Here, nano-vests made of titania formed around gold nanostars are computer designed, synthesized, and characterized to illustrate the concept.
Contact Information arthur.montazeri@berkeley.edu
Advisor Roya Maboudian, Carlo Carraro

 
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NanoTechnology: Materials, Processes & Devices
Project IDBPN843
Project Title Non-Enzymatic Electrochemical Sensors Based on Wearable Carbon Textile
Status Continuing
Funding Source NSF
Keywords electrochemical sensor, carbon fiber textile
Researchers Hu Long, Sinem Ortaboy
Abstract Nowadays, electrochemical sensors play an important role in wide range of potential applications, especially in point-of-care applications for real-time human physiology monitoring. Considerable efforts have been devoted not only to improve their sensitivity, response time, stability and biocompatibility but also to develop new materials which enable the researchers to create smarter multifunctional devices. In this regard, flexible textiles such as carbon fiber sheet-integrated electrodes are promising materials due to their good conductivity, low-cost, biocompatibility and stability even under harsh environmental conditions. In this study, flexible carbon-based textile incorporating electroactive species are being developed as the electrode for electrochemical sensor and biosensor applications.
Contact Information longhu@berkeley.edu
Advisor Roya Maboudian, Carlo Carraro

 
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NanoTechnology: Materials, Processes & Devices
Project IDBPN835
Project Title Silicon Carbide Passivated Electrode for Thermionic Energy Conversion
Status Continuing
Funding Source Federal
Keywords Silicon Carbide, Tungsten, Thermionic Emission, LPCVD, High-Temperature
Researchers Steven R. DelaCruz, Ping Cheng, Dungsheng Tsai, Zhongtao Wang
Abstract Thermionic energy converters (TECs) are based on the emission of electrons from a hot electrode (cathode) into a vacuum gap and their collection by a cooler electrode (anode), delivering an electric current through the load. In this process, they convert heat directly into electricity and have the potential to achieve high efficiencies comparable to those of conventional heat engines. We have initiated a highly collaborative project to develop a microfabricated, close-gap thermionic energy converter for directly converting heat from a combustion source into electricity. One of the key challenges is associated with the cathode which needs to be highly conductive and survive temperatures as hot as 2000 °C in an oxidizing environment. While tungsten is an attractive choice for the cathode, it readily oxidizes under the envisioned conditions. Owing to its chemical inertness and mechanical strength at high temperatures, silicon carbide is an effective option for electrode passivation. In this work, we are developing processes for fabricating a SiC-protected tungsten electrode, exploring the necessity and effectiveness of interdiffusion barriers, and investigating its long-term stability under harsh environments.
Contact Information sdelacruz@berkeley.edu, maboudia@berkeley.edu, carraro@berkeley.edu, pingcheng@berkeley.edu, dungshe
Advisor Roya Maboudian, Carlo Carraro

 
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Physical Sensors & Devices
Project IDBPN876 New Project
Project Title Metal-organic frameworks: A highly tunable class of materials for chemical sensing with high selectivity
Status New
Funding Source State
Keywords Sensing, Metal-organic frameworks, tunability, chemistry, ChemFET, CS-FET
Researchers David Gardner
Abstract A classic challenge in gas sensing is tunability of sensing material to suit the specific application. A new class of materials, metal-organic frameworks (MOFs), can take on thousands of forms, each with unique properties. Metal-organic frameworks are comprised of metal-cluster nodes connected by organic linkers. Changing the metal cluster or the organic linker can modulate the sensing response by at least two mechanisms: one, the metal cluster determines what gasses can bind to the material, and second, the length and functional groups of the organic linker control which gasses can enter the MOF. Guest molecules diffuse through the material and modulate the MOF’s surface potential, which can be sensed by a device, such as CS- FET (developed by Dr. Hossain Fahad and Prof. Ali Javey). Recent progress shows that the MOF sensing layer is sensitive to acidic gases, e.g. NO2, and has an ultra-low power requirement. Future work will focus on growing a library of synthesis techniques and gas sensing responses to target different applications.
Contact Information dwg@berkeley.edu
Advisor Roya Maboudian, Carlo Carraro, Ali Javey

 
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Physical Sensors & Devices
Project IDBPN743
Project Title Highly Responsive pMUTs
Status Continuing
Funding Source BSAC Member Fees
Keywords Piezoelectric Micromachined Ultrasonic Transducers (pMUTs), curved pMUTS, spherical piezoelectric elastic shells, bimorph pMUTs, dual electrode bimorph pMUT
Researchers Benjamin Eovino, Yue Liang
Abstract Ultrasonics has been realized as a nondestructive measurement method for a variety of applications, such as medical imaging, healthcare monitoring, structural testing, range finding, and motion sensing. Furthermore, high intensity ultrasound can be used in therapeutic treatments, such as lithotripsy for kidney stone comminution, hyperthermia for cancer therapy, high-intensity focused ultrasound (HIFU) for laparoscopic surgery, and transcranial sonothrombolysis for brain stroke treatment. MEMS ultrasonic transducers are known to have several pronounced advantages over the conventional ultrasound devices, namely higher resolution, higher bandwidth, and lower power consumption. The main purpose of this project is to develop new architectures of Piezoelectric Micromachined Ultrasonic Transducers (pMUT) with higher electro-mechano-acoustical energy efficiency and increased sensitivity while using CMOS-compatible fabrication technology, making them suitable for battery-powered handheld devices. The specific focus is on increasing the electromechanical coupling, bandwidth, and acoustic pressure output in aims of creating power- efficient hand-held medical devices for diagnosis/therapy.
Contact Information beovino@berkeley.edu, lunaliang93@berkeley.edu
Advisor Liwei Lin

 
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Micropower
Project IDBPN782
Project Title Flexible load-bearing energy storage fabrics
Status Continuing
Funding Source Army/ARL
Keywords Flexible supercapacitor, Wearable electronics, Structural energy storage, Carbon fiber
Researchers Caiwei Shen, Weihua Cai
Abstract The power source is a bottleneck for the successful development of flexible electronics. Instead of using rigid and bulky batteries, flexible multifunctional devices that store energy and bear loads at the same time provide better solutions by working as powering structural components. Here we demonstrate the woven supercapacitor fabrics featuring high flexibility comparable to that of wearable textiles, high tensile strength of over 1GPa, high failure pressure of 500MPa, and fast charging within seconds. The supercapacitor fabrics can power all kinds of wearable electronics, or be used in other applications that desire load- bearing ability and arbitrary form-factor design for the power systems.
Contact Information shencw10@berkeley.edu
Advisor Liwei Lin

 
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Physical Sensors & Devices
Project IDBPN799
Project Title 3D Printed Microsensors
Status Continuing
Funding Source DARPA
Keywords Microsensor, 3D printing, Metallization
Researchers Dongwoo Shin, Huiliang Liu, Renxiao Xu
Abstract Our goal is to develop high-throughput 3D printing methods for building microsensors for various applications. This project will involve formulating new inks/solutions and investigating optimal printing conditions for 3D printing methods such as inkjet and electrohydrodynamic (EHD) printing.
Contact Information dongwooshin@berkeley.edu
Advisor Liwei Lin

 
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NanoTechnology: Materials, Processes & Devices
Project IDBPN672
Project Title Solar Hydrogen Production by Photocatalytic Water Splitting
Status Continuing
Funding Source KAUST
Keywords Solar energy, photocatalysis, nano materials
Researchers Emmeline Kao
Abstract Hydrogen is a promising, environmentally-friendly fuel source for replacing fossil fuels in transportation and stationarypower applications. Currently, most hydrogen is produced from non-renewable sources including natural gas, oil, and coal. Photoelectrochemical (PEC) water splitting is a new renewable energy technology that aims to generate hydrogen from water using solar energy. When light is absorbed by the photocatalyst, an electron-hole pair is generated that interacts with water molecules in a surface reduction-oxidation reaction to decompose the water into hydrogen and oxygen. The current challenge in PEC water splitting is finding low-cost, stable materials with good visible light absorption and high efficiency for water splitting. Polymers such as thiophene have demonstrated promising capabilities as photocatalysts due to its favorable band structure for both solar absorption and photocatalysis by electropolymerizing films for vertical transfer of electrons. This project aims to improve the performance of PEC devices for water splitting by developing new high surface area photoelectrodes surrounded by a thin layer of electroplated polymers.
Contact Information kao@berkeley.edu
Advisor Liwei Lin

 
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Microfluidics
Project IDBPN774
Project Title Applications of 3D Printed Integrated Microfluidic Circuitry, Finger-Powered Pumps, and Mixers
Status Continuing
Funding Source BSAC Member Fees
Keywords Lab-on-a-Chip, 3D Printing, Microfluidics, Low-power, Passive, Mixing, biosensing
Researchers Eric Sweet, Jacqueline Elwood, Ryan Jew, Rudra Mehta
Abstract In this ongoing project we have previously developed a new class of three-dimensional modular fluidic operators (i.e. fluidic diodes, capacitors and transistors); passive 3D internally-rifled mixers; and have previously demonstrated low- cost one-way pumping and mixing systems powered solely by the operator’s finger. Currently, we aim to develop our easy-to-fabricate 3D microfluidic systems into functional biosensors via straight-forward integration with conductive polymer electrodes. Here, we present our preliminary investigations into the development of entirely 3D printed microfluidic salivary point-of-care diagnostic tools, specifically for the determination of salivary alcohol content (SAC) and salivary lactate content (SLC). In law enforcement, blood alcohol content (BAC) is routinely determined indirectly by measurement of breath alcohol content (BrAC) using commercialized breathalyzer technology. However, measurement of SAC has a nearly 1:1 correlation with BAC, much closer than BAC:BrAC, over 2,000:1. Therefore, SAC could prove to be a more reliable metric of sobriety than BrAC. In addition, for diabetic patients, continuous home monitoring blood glucose levels necessitates repeated finger pricking and blood testing. However, researchers have previously established measurable correlations between salivary lactic acid levels and blood glucose levels, opening the possibility for non-invasive, point-of-care salivary-based blood sugar monitoring. In this project, we aim to demonstrate proof-of-concept salivary diagnostic prototypes comprised of our previously-demonstrated 3D microfluidic technology and composite conductive polymer electrodes. SAC will be determined via pH-sensitive PEDOT:PSS/PANI polymer electrodes, and SLC will be determined via hydrogen peroxide-sensitive PEDOT:PSS/PAA polymer electrodes. Upon further development, such designs could prove critical tools in resolving the foremost commercial limitations of conventional microfluidic point-of-care diagnostic devices, specifically for salivary diagnostics.
Contact Information ericsweet@berkeley.edu, jacqueline_elwood@berkeley.edu, rjew@berkeley.edu, Rudra.Mehta@berkeley.edu,
Advisor Liwei Lin

 
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Microfluidics
Project IDBPN846
Project Title 3D Printed Biomedical and Diagnostic Systems
Status Continuing
Funding Source BSAC Member Fees
Keywords
Researchers Jacqueline Elwood, Eric C. Sweet, Ryan Jew
Abstract Enzyme-linked immunosorbent assay (ELISA) kits have wide applications in medical diagnostics, quality-control of produce, and toxicology. These kits, however, are expensive, highly complex, and require large sample volumes in order to process data. To overcome these drawbacks, microfluidic lab-on-chip platforms have been developed to quantify antibody-antigen binding interactions using microlitre volumes of analyte. These devices rely on standard soft-lithography or MEMS-based manufacturing methods, which are becoming increasingly more time consuming, labor intensive, and costly in the face of additive manufacturing processes. Additionally, current methods rely on immunofluorescence or chromogenic detection to measure antibody-antigen binding success, but these methods are time consuming, expensive, or subject to cross-reactivity or biofouling. We aim to develop a novel fully 3D printed thermoelectric biosensor for antibody-antigen binding quantification as an alternative micro-ELISA diagnostic tool. In this project, we will demonstrate that our 3D printed thermoelectric device can detect the streptavidin-biotin binding interaction as an initial proof-of-concept. Previous thermoelectric sensors for detection of bioreactions utilize non- biocompatible materials, which require the thermopile to be placed away from the channel, resulting in lower sensitivity systems. Utilizing a biocompatible PEDOT:PSS-based composite as our thermoelectric material, we aim to integrate the thermopile into the microchannel itself. Additionally, 3D printing will enable us to design 3D thermopile geometries that cannot be otherwise achieved with traditional soft-lithography. By eliminating the need for optics or external energy sources coupled with the use of low-cost additive manufacturing, we aim to develop a simple lab-on- chip alternative to traditional ELISA kits.
Contact Information jacqueline_elwood@berkeley.edu, ericsweet@berkeley.edu, rjew@berkeley.edu
Advisor Liwei Lin

 
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Wireless, RF & Smart Dust
Project IDBPN840
Project Title W-Band Additive Vacuum Electronics
Status Continuing
Funding Source DARPA
Keywords
Researchers Ilbey Karakurt
Abstract Radio frequency (RF) devices for high frequency applications such as satellite communication and mobile and ground uplinks have brought about the demand for higher power handling capabilities and increased efficiency in these devices. Technologies for creating low cost, advanced millimeter wave electronics devices without sacrificing quality or performance has thus grown. Direct metal additive manufacturing techniques, such as electron beam melting, has been projected to be capable of fabricating such devices. Key concerns regarding these techniques are the requirements for high purity materials (99.6%), small feature sizes (~2um) and low surface roughness (less than 200 nm for 95 GHz devices and above) for high frequency applications. This project will demonstrate that direct metal additive manufacturing combined with magnetic field assisted abrasive polishing techniques can be used to provide a rapid manufacturing process for fully enclosed and cooled complex interaction structures to be used in high frequency applications.
Contact Information ilbeykarakurt@berkeley.edu
Advisor Liwei Lin

 
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Micropower
Project IDBPN855
Project Title Flexible Sensors and Energy Harvesters
Status New
Funding Source BSAC Member Fees
Keywords Energy harvesting, flexible, stretchable, sensor
Researchers Junwen Zhong, Ilbey Karakurt, Yichuan Wu, Nathaniel Liu, Mingjing Qi
Abstract Wearable and implantable devices are expected to become more abundant due to developments in materials and microfabrication technologies. However, battery replacement is a major problem for these systems. Shrinking the size of sensors and actuators also reduces their power requirements, and it makes energy harvesting a viable solution as a renewable power source. In this project, we work with various sets of flexible materials to develop 1) an energy harvester to generate electrical power to either extend battery life or eliminate the battery; 2) sensors to detect biological signals from different parts of the body.
Contact Information lbeker@berkeley.edu, junwenzhong@berkeley.edu, ilbeykarakurt@berkeley.edu, yichuanwu@berkeley.edu
Advisor Liwei Lin

 
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Physical Sensors & Devices
Project IDBPN877 New Project
Project Title Pulse Acquisition and Diagnosis for Health Monitoring
Status New
Funding Source Fellowship
Keywords Wearable Devices, Piezo Electret Sensor, Pulse Wave Acquisition, Traditional Chinese Medicine
Researchers Yao Chu, Junwen Zhong, Yu Song, Huiliang Liu
Abstract Traditional Chinese medicine has been existing for more than two thousand years and one of the important diagnostic methods is the pulse diagnosis. It generally takes decades of trainings for a practitioner to master this skill as pulse acquisition and diagnosis require long-term experiences and are very subjective. This project aims to use the combination of pulse acquisition and big data analytics to realize the traditional Chinese medicine practices. The hardware part will be based on MEMS-type wearable sensors to be embedded in a smartwatch or wristband to mimic Chinese doctor’s three fingers to acquire the detail wave-forms of the pulse on the wrist. The learning and practicing will be achieved by the training process on the multi-dimensional pulse-wave data. We have developed a flexible and self-powered pressure sensor based on a sandwich-structured piezo-electret, which exhibits high sensitivity and excellent stability for human pulse acquisitions.
Contact Information chuyao@berkeley.edu, junwenzhong@berkeley.edu, songyu_elaine@hotmail.com, liuhl@berkeley.edu, lwlin@
Advisor Liwei Lin

 
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Micropower
Project IDBPN742
Project Title Novel Methods to Synthesis Transition Metal Dichalcogenide and Transition Metal Carbide for Energy Storage Applications
Status Continuing
Funding Source BSAC Member Fees
Keywords
Researchers Xining Zang, Minsong Wei
Abstract The field of 2D materials have witnessed tremendous efforts of research in past several years, transition metal dichalcogenide (TMDC) and transition metal carbides are the most famous two families 2D material besides graphene. The vision of this project is developing "tolerant" and sustainable method to synthesis those kinds of materials with high quality/yield and design applications compatible with the fabrication approaches. Till now, we have been developing atomic layer deposition, self-assembly coupled CVD, and laser ablation methods to synthesis a series of 2D materials including TiS2, Mo3C2, Mo2C and etc. We specify their application in energy storage and conversion including supercapacitors and catalyst for hydrogen evolution and oxygen evolution reactions.
Contact Information xining.zang.me@berkeley.edu
Advisor Liwei Lin

 
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NanoTechnology: Materials, Processes & Devices
Project IDBPN860
Project Title Foldable Paper Electronics by Direct-Write Laser Patterning
Status New
Funding Source BSAC Member Fees
Keywords
Researchers Xining Zang, Yao Chu, Renxiao Xu, Minsong Wei, Junwen Zhong
Abstract Paper electronics have been a popular subject in recent years, with various works concentrating on the printing of additive materials on papers. Here, we show a drastically different approach by a direct-write laser patterning process on paper. Innovative claims are: (1) direct conversion of non-conductive paper to conductor by laser; (2) a variety of foldable architectures and devices using the as-fabricated paper electronics; and (3) among various possible basic device applications, we show a foldable triboelectricity generator and a folded supercapacitor as the potential paper-based power source for paper electronics, a wireless humidity sensor, and a heavy metal ion detector as working components.
Contact Information xining.zang.me@berkeley.edu
Advisor Liwei Lin

 
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Physical Sensors & Devices
Project IDBPN772
Project Title Graphene for Room Temperature Gas Sensors
Status Continuing
Funding Source BSAC Member Fees
Keywords Chemical Sensor, Gas Sensor, Graphene FET, Selectivity
Researchers Yumeng Liu, Takeshi Hayasaka
Abstract As air pollution from industrial and automobile emission becomes more and more severe, the personalized, integrated gas sensor is desirable for everyone to monitor everyday's air quality as well as their personal health condition non-invasive. Such sensor should have the desirable features like energy efficient, miniature size, accurate response (down to ppm level), and selectivity. Traditional bulk MOX based gas sensor works in the temperature range of 300 to 400 oC, which requires large amount of energy to power the heater. We here propose using graphene based field effect transistor as label-free sensor platform, to detect gas selectively by measuring its electrical properties at room temperature.
Contact Information yumengliu@berkeley.edu
Advisor Liwei Lin

 
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BioMEMS
Project IDBPN870 New Project
Project Title Hot Embossed Thermoplastic Bubble-Actuated Micropump
Status New
Funding Source BSAC Member Fees
Keywords Hot embossed microdevice, bubble micro pump, electrolysis pump, plastic bubble pump
Researchers Jackelin Amorin Cotrina, Marc S. Chooljian
Abstract Advances in technology have allowed for development of health diagnostics microdevices, but implementation of microdevices for drug delivery is relatively new. Continuous drug delivery often requires large and complex pumps, making development of micropumps desirable. Similarly, commonly used materials such as silicon are too expensive for mass production of disposable devices, and polydimethylsiloxane (PDMS) is not compatible with some pharmaceutical drugs due to partitioning effects into the PDMS matrix. Thermoplastic incorporation into microdevices production is more cost efficient compared to silicon, and can be tuned to have a variety of chemical, optical, and mechanical properties, in contrast to PDMS. In this research we will be testing the efficiency of new bio-safe drug dispensing microdevice which works with an incorporated micro bubble pump system. The bubble pump system uses electrolysis of water, in which water is broken down into hydrogen and oxygen gas to create a pressure change that displaces a volume of liquid equal to the volume of gas formed. Bubble pumps, unlike mechanical pumps, have no moving parts and are therefore more easily miniaturized. The devices are fabricated using a modified hot embossing method developed by our lab, which allows microelectrodes integration into thermoplastic fluidic channels to create electrolysis chambers. Development of a functional microbubble pump that uses the advantages of thermoplastics will lead to improved development of bio-safe drug dispensing microdevices.
Contact Information jamorin@berkeley.edu
Advisor Dorian Liepmann

 
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Microfluidics
Project IDBPN863
Project Title In Situ Gold Plating of Microfluidic Devices
Status Continuing
Funding Source BSAC Member Fees
Keywords Electrodeposition, Gold, Microfluidic
Researchers Marc Chooljian
Abstract Microfluidic devices are currently limited in their application potential by the lack of appropriate sensors or integrated electrodes. Building on the work of Dr. Dorian Liepmann's lab in electrodeposited electrodes and hot embossing, where deposited electrodes in contact with fluid channels are composed primarily of nickel, we endeavor to develop a novel process for gold-electroplating those nickel surfaces, within the channel, after the chip has been constructed (in situ). By using this process the metallic surfaces in contact with the electrolyte in the channel can be chemically passivated with a thin gold layer, thus limiting the participation of the device's materials in its operation. This process may also have the added benefit of sealing the nickel-plastic edges where bonding is sub optimal and leaking can occur. This process will contribute to further advances in both the mass-production and prototyping of plastic-based BioMEMS.
Contact Information mschooljian@berkeley.edu
Advisor Dorian Liepmann

 
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Microfluidics
Project IDBPN839
Project Title Flow Control in Plastic Microfluidic Devices Using Thermosensitive Gels
Status Continuing
Funding Source BSAC Member Fees
Keywords
Researchers Marc Chooljian
Abstract Our new microfabrication process can integrate electronics into plastic devices, simplifying on chip sensing and actuation. Traditional microfluidic prototyping (PDMS soft-lithography) requires large off chip components for active flow control. These components impose scalability limitations. Leveraging thermo- gelling polymers and integrated resistive heaters we can implement on chip active flow control. These polymers, poloxamers, are nonionic triblock copolymers known for their temperature dependent self- assembling and thermo-gelling behavior. Poloxamers can quickly (<30ms) undergo a phase transition into a gel-like substance over a temperature change of two degree Celsius. The viscosity rapidly increases by a 1000-fold, effectively stopping flow. Furthermore, the transition temperature can be easily adjusted by varying poloxamer concentration, allowing for precise thermal control. Using targeted heating with our integrated resistive heaters, we can leverage the phase transition temperature to create rapid reversible valves. These devices expand microfluidic prototyping capabilities in fields such as mixers, fluidic logic, cell culturing, and imaging.
Contact Information mschooljian@gmail.com
Advisor Dorian Liepmann

 
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BioMEMS
Project IDBPN729
Project Title Development of Microfluidic Devices with Embedded Microelectrodes using Electrodeposition and Hot Embossing
Status Continuing
Funding Source BSAC Member Fees
Keywords Packaging, Microfluidics, Electrodes, Hot Embossing
Researchers Marc Chooljian
Abstract The use of microfluidic devices has experienced a tremendous increase over the last years, especially valuable for healthcare applications. In this context plastic materials are increasingly relevant especially for large scale fabrication and commercialization. However plastics are still not widely used at the research level due to the lack of available inexpensive industrial–like fabrication equipment. In this work we describe a rapid and highly cost-effective approach for fabricating plastic microfluidic devices with embedded microelectrodes allowing 2D and 3D configurations. We present an interdigitated microelectrode configuration applied to impedance cytometry and cellular electroporation/lysis on chip devices as an example of the great potential of this technology. Our long-term goals are to further explore the potential of hot-embossed microscale devices as platforms for complete BioMEMS devices. This includes the integration of functionalized elements and silicon-based biosensors. A variety of functional coatings will be developed to apply integrated electrodes to many different sensing applications.
Contact Information mschooljian@berkeley.edu
Advisor Dorian Liepmann

 
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Physical Sensors & Devices
Project IDBPN851
Project Title High Fill Factor Piezoelectric Micromachined Ultrasonic Transducers on Transparent Substrates
Status Continuing
Funding Source Industry
Keywords AlN, piezoelectric, ultrasonic, PMUT, glass
Researchers Guo-Lun Luo
Abstract This study presents a high fill-factor array of aluminum nitride (AlN) piezoelectric micromachined ultrasonic transducers (PMUTs) fabricated on a transparent substrate. PMUTs with diameters ranging from 40 microns to 100 microns were fabricated, resulting in resonant frequencies from 3 MHz to 18 MHz in air. A high fill-factor of 62% was achieved. Immersed pulse-echo experiments were conducted at 2.5 MHz.
Contact Information glluo@ucdavis.edu
Advisor David A. Horsley

 
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Physical Sensors & Devices
Project IDBPN880 New Project
Project Title Synchronization in a Micromachined Resonators
Status Continuing
Funding Source BSAC Member Fees
Keywords Nonlinear Oscillation, Synchronization
Researchers Parsa Taheri-Tehrani
Abstract Synchronization is a well-known phenomenon in nonlinear dynamics that is used to lock the frequencies of two oscillators for frequency stabilization applications. The simplest evidence of such frequency entrainment occurs between a self-sustained oscillator and an external tone2, when the latter is swept around the resonance frequency of the oscillator. Synchronization between two oscillators with frequencies related by an integer ratio can occur but requires coupling between the two modes. We present an experimental study of synchronization between two resonance modes of a single resonator, where the second mode is nearly the third harmonic of the first mode. Due to intrinsic electro-mechanical coupling between the two modes, synchronization will occur for a specific frequency range known as synchronization range. We show by increasing the amplitude of the first mode in the nonlinear Duffing regime, the synchronization range will increase.
Contact Information ptaheri@ucdavis.edu
Advisor David A. Horsley

 
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Physical Sensors & Devices
Project IDBPN785
Project Title Scandium AlN (ScAlN) for MEMS
Status Continuing
Funding Source BSAC Member Fees
Keywords Piezoelectric, MEMS, AlN, ScAlN, Thin films, PMUT
Researchers Qi Wang
Abstract The goal of this project is to design, fabricate and characterize novel MEMS devices based on scandium aluminum nitride (ScAlN) thin films. ScAlN thin film is a promising piezoelectric material due to its CMOS process compatibility, low relative permittivity and high piezoelectric coefficient and enables better performance of piezoelectric MEMS devices.
Contact Information qixwang@ucdavis.edu, dahorsley@ucdavis.edu
Advisor David A. Horsley

 
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Physical Sensors & Devices
Project IDBPN628
Project Title Novel Ultrasonic Fingerprint Sensor Based on High-Frequency Piezoelectric Micromachined Ultrasonic Transducers (PMUTs)
Status Continuing
Funding Source BSAC Member Fees
Keywords piezoelectric, ultrasound transducers, medical imaging, fingerprint sensors
Researchers Xiaoyue (Joy) Jiang, Qi Wang
Abstract This project presents the first MEMS ultrasonic fingerprint sensor with the capability to image epidermis and dermis layer fingerprints. The sensor is based on a piezoelectric micromachined ultrasonic transducer (PMUT) array that is bonded at wafer- level to complementary metal oxide semiconductor (CMOS) signal processing electronics to produce a pulse-echo ultrasonic imager on a chip. To meet the 500 DPI standard for consumer fingerprint sensors, the PMUT pitch was reduced by approximately a factor of two relative to an earlier design. We conducted a systematic design study of the individual PMUT and array to achieve this scaling while maintaining a high fill-factor.
Contact Information joy.jiang@berkeley.edu, dahorsley@ucdavis.edu
Advisor David A. Horsley

 
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Physical Sensors & Devices
Project IDBPN849
Project Title Large-Amplitude PZT PMUTs
Status Continuing
Funding Source BSAC Member Fees
Keywords PMUT, piezoelectric, PZT
Researchers Yuri Kusano
Abstract Ultrasonic transducers are widely used in various applications including medical imaging, nondestructive evaluation, object/gesture recognition, automotive, and range-finding. Compared to conventional capacitive micromachined ultrasonic transducers (CMUTs), piezoelectric micromachined ultrasonic transducers (PMUTs) have an advantage that they can be utilized without high bias voltages, resulting in simpler electronic interfaces. This project targets air-coupled PMUTs with wide bandwidth to achieve high axial resolution in pulse-echo imaging, where air-coupled transducers typically operate in the frequency range of 40 kHz to 800 kHz. Regarding the piezoelectric material, the thin-film PZT (lead-zirconate-titanate) is widely used for piezoelectric devices and well-known to have higher piezoelectric coefficient e31,f as well as higher transmitting efficiency than those of another major piezoelectric material AlN. In this project, we design, model, and characterize PZT PMUTs with a large displacement amplitude for in-air operation to improve the sensor performance in pulse-echo imaging system.
Contact Information ykusano@ucdavis.edu, dahorsley@ucdavis.edu
Advisor David A. Horsley

 
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Physical Sensors & Devices
Project IDBPN817
Project Title Ultra-Low Power AlN MEMS-CMOS Microphones and Accelerometers
Status Continuing
Funding Source DARPA
Keywords AlN, MEMS-CMOS, microphone, accelerometer, subthreshold, low power
Researchers Yuri Kusano
Abstract State-of-the-art (SOA) physical sensors used to monitor changes in the environment require active electronics that continuously consume power (in the order of mW) limiting the sensor lifetime to months or less. This project targets the integration of low frequency sensors with wake-up electronics that operates below 10nW (50dB lower than the SOA) and achieve high probability of detection (POD) (>95%) and low false alarm rate (FAR) (<1h^-1). To improve the sensor performance at low frequencies we design piezoelectric AlN MEMS microphones and accelerometers with high voltage sensitivities, CMOS circuits with low bias current that operate in subthreshold, and lower the interconnect parasitics (<50fF) by directly bonding both MEMS and CMOS wafers. In particular, the sensor output voltage is boosted by 1) segmenting and stacking the electrodes in series, and 2) optimizing the size, number of electrodes and materials that form the multilayer structure. Regarding to the circuit, we exploit the multiple threshold voltages that are available in the process to reduce leakage on switches, increase input gain, and decrease overdrive voltage in current mirrors. Finally, we achieve the detection specs (POD and FAR) by implementing a programmable 4-stage comparator that allows us to adjust the circuit threshold according to the maximum level of input signal.
Contact Information ykusano@ucdavis.edu, dahorsley@ucdavis.edu
Advisor David A. Horsley