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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 December 05, 2016

Number of records: 78
POSTERRESEARCH THRUSTABSTRACT
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PROJECT MATERIALS
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PROJECT TITLEADVISOR
1Wireless, RF & Smart DustBPN840BPN840 WebsiteW-band Additive Vacuum Electronics New ProjectLiwei Lin
2MicrofluidicsBPN846BPN846 Website3D Printed Biomedical and Diagnostic Systems New ProjectLiwei Lin
3MicrofluidicsBPN774BPN774 Website3D Printed Integrated Microfluidics: Circuitry, Finger-Powered Pumps and MixersLiwei Lin
4MicropowerBPN742BPN742 Website3D Carbon-Based Materials for Electrochemical ApplicationsLiwei Lin
5MicropowerBPN782BPN782 WebsiteFlexible Micro SupercapacitorsLiwei Lin
6NanoTechnology: Materials, Processes & DevicesBPN672BPN672 WebsiteSolar Hydrogen Production by Photocatalytic Water SplittingLiwei Lin
7NanoTechnology: Materials, Processes & DevicesBPN800BPN800 WebsiteSolution Processed Transparent ElectronicsLiwei Lin
8Physical Sensors & DevicesBPN799BPN799 Website3D Printed MicrosensorsLiwei Lin
9Physical Sensors & DevicesBPN772BPN772 WebsiteGraphene for Room Temperature Gas SensorsLiwei Lin
10Physical Sensors & DevicesBPN743BPN743 WebsiteHighly Responsive pMUTsLiwei Lin
11BioMEMSBPN685BPN685 WebsiteReal-Time Intraoperative Fluorescent Imager for Microscopic Residual Tumor in Breast CancerBernhard E. Boser, Mekhail Anwar
12Physical Sensors & DevicesBPN608BPN608 WebsiteFM GyroscopeBernhard E. Boser
13NanoPlasmonics, Microphotonics & ImagingBPN458BPN458 WebsiteOptical Antenna-Based nanoLEDMing C. Wu, Ali Javey
14NanoPlasmonics, Microphotonics & ImagingBPN751BPN751 WebsiteLarge-scale Silicon Photonic MEMS Switch with Sub-Microsecond Response TimeMing C. Wu
15NanoPlasmonics, Microphotonics & ImagingBPN721BPN721 WebsiteElectronic-Photonic Heterogeneous Integration (EPHI) for High Resolution FMCW LIDARMing C. Wu
16NanoTechnology: Materials, Processes & DevicesBPN825BPN825 WebsiteDirect On-Chip Optical Synthesizer (DODOS)Ming C. Wu
17NanoPlasmonics, Microphotonics & ImagingBPN788BPN788 WebsiteOptical Phased Array for LIDARMing C. Wu
18NanoPlasmonics, Microphotonics & ImagingBPN703BPN703 WebsiteDirectly Modulated High-Speed nanoLED Utilizing Optical Antenna Enhanced Light EmissionMing C. Wu
19MicrofluidicsBPN552BPN552 WebsiteLight-Actuated Digital Microfluidics (Optoelectrowetting)Ming C. Wu
20NanoPlasmonics, Microphotonics & ImagingBPN836BPN836 WebsiteNanocrescent antenna for nanofocusing of excitation radiation and concentrate upconversion emission New ProjectLuke P. Lee
21BioMEMSBPN829BPN829 WebsiteIntegrated Multiplexed Optical Microfluidic System (iMOMs) for Dengue DiagnosisLuke P. Lee
22MicrofluidicsBPN824BPN824 WebsiteInvestigation of Dengue Infection’s Neurological Complications via a Comprehensive in-vitro Brain ModelLuke P. Lee
23BioMEMSBPN804BPN804 WebsiteA Rapid, Integrated Molecular Diagnostic for Gram-Negative Pathogen Detection and Identification Based on Antibody-Based Capture and Photonic PCRLuke P. Lee
24MicrofluidicsBPN730BPN730 WebsiteMicrofluidic Blood Plasma Separation for Point-of-Care DiagnosticsLuke P. Lee
25NanoPlasmonics, Microphotonics & ImagingBPN809BPN809 WebsitePhotonic Cavity Bioreactor for High-throughput Screening of MicroalgaeLuke P. Lee
26Package, Process & MicroassemblyBPN354BPN354 WebsiteThe Nanoshift Concept: Innovation through Design, Development, Prototyping and Fabrication of MEMS, Microfluidics, Nano- and Clean TechnologiesMichael D. Cable
27MicrofluidicsBPN839BPN839 WebsiteFlow Control in Plastic Microfluidic Devices using Thermosensitive Gels New ProjectDorian Liepmann
28BioMEMSBPN847BPN847 WebsiteA 3D Printed Microfluidic-Based Blood Filtration Device Examines the Effect of Blood Components in Aging Process New ProjectDorian Liepmann
29MicrofluidicsBPN711BPN711 WebsitePoint-of-Care System for Quantitative Measurements of Blood Analytes Using Graphene-Based SensorsDorian Liepmann
30BioMEMSBPN729BPN729 WebsiteDevelopment of Microfluidic Devices with Embedded Microelectrodes using Electrodeposition and Hot EmbossingDorian Liepmann
31MicrofluidicsBPN732BPN732 WebsiteThe Role of Erythrocyte Size and Shape in Microchannel Fluid DynamicsDorian Liepmann
32Physical Sensors & DevicesBPN817BPN817 WebsiteUltra-Low Power AlN MEMS-CMOS Microphones and AccelerometersDavid A. Horsley, Rajeevan Amirtharajah
33Physical Sensors & DevicesBPN849BPN849 WebsiteLarge-amplitude PZT PMUTs New ProjectDavid A. Horsley
34Physical Sensors & DevicesBPN628BPN628 WebsiteNovel Ultrasonic Fingerprint Sensor Based on High-Frequency Piezoelectric Micromachined Ultrasonic Transducers (PMUTs)David A. Horsley
36Physical Sensors & DevicesBPN785BPN785 WebsiteScandium-doped AlN for MEMSDavid A. Horsley
37Physical Sensors & DevicesBPN599BPN599 WebsiteMEMS Electronic Compass: Three-Axis MagnetometerDavid A. Horsley
38Physical Sensors & DevicesBPN603BPN603 WebsiteMicro Rate-Integrating GyroscopeDavid A. Horsley
39Physical Sensors & DevicesBPN812BPN812 WebsiteImproving Micro-Oscillators Performance By Exploiting NonlinearityDavid A. Horsley
40NanoTechnology: Materials, Processes & DevicesBPN834BPN834 WebsiteDirect Formation of Pore-Controllable Mesoporous SnO2 for Gas Sensing Applications New ProjectRoya Maboudian, Carlo Carraro
41NanoTechnology: Materials, Processes & DevicesBPN843BPN843 WebsiteNon-enzymatic Electrochemical Sensors Based on Wearable Carbon Textile New ProjectRoya Maboudian, Carlo Carraro
42NanoTechnology: Materials, Processes & DevicesBPN835BPN835 WebsiteSilicon Carbide Passivated Electrode for Thermionic Energy Conversion New ProjectRoya Maboudian, Carlo Carraro
43NanoTechnology: Materials, Processes & DevicesBPN837BPN837 WebsiteMetal oxide-coated carbonized-silicon nanowires as high-performance micro-supercapacitor New ProjectRoya Maboudian, Carlo Carraro
44Physical Sensors & DevicesBPN842BPN842 WebsiteConductometric gas sensing behavior of WS2 aerogel New ProjectRoya Maboudian, Carlo Carraro
45NanoTechnology: Materials, Processes & DevicesBPN827BPN827 WebsiteMetal Oxide-decorated Silicon Carbide Nanowires Electrode for The Applications on Electrochemical Energy StorageRoya Maboudian, Carlo Carraro
47NanoTechnology: Materials, Processes & DevicesBPN790BPN790 WebsiteLow Power Microheater-Based Platform for Gas SensingRoya Maboudian, Carlo Carraro
48NanoTechnology: Materials, Processes & DevicesBPN813BPN813 WebsiteNovel Hierarchical Metal Oxide Nanostructures for Conductometric Gas SensingRoya Maboudian
49NanoTechnology: Materials, Processes & DevicesBPN832BPN832 WebsiteGold-Mediated Exfoliation of Ultralarge Optoelectronically-Perfect Monolayers New ProjectAli Javey
50Physical Sensors & DevicesBPN818BPN818 WebsiteFully-Integrated Wearable Sensor Arrays for Multiplexed In Situ Perspiration AnalysisAli Javey
52NanoTechnology: Materials, Processes & DevicesBPN822BPN822 WebsiteMonolayer Semiconductor OptoelectronicsAli Javey
54NanoTechnology: Materials, Processes & DevicesBPN777BPN777 WebsiteNonepitaxial Growth of Single Crystalline III-V Semiconductors onto Insulating SubstratesAli Javey
55Physical Sensors & DevicesBPN747BPN747 WebsiteElectronic Skin: Fully Printed Electronic Sensor NetworksAli Javey
56NanoTechnology: Materials, Processes & DevicesBPN704BPN704 WebsiteVapor-Liquid-Solid Growth of Polycrystalline Indium Phosphide Thin Films on MetalAli Javey
57Physical Sensors & DevicesBPN770BPN770 WebsiteChemical Sensitive Field Effect Transistor (CS-FET)Ali Javey
58Wireless, RF & Smart DustBPN828BPN828 WebsiteZero Quiescent Power Micromechanical ReceiverClark T.-C. Nguyen
60Wireless, RF & Smart DustBPN540BPN540 WebsiteTemperature-Stable Micromechanical Resonators and FiltersClark T.-C. Nguyen
61Wireless, RF & Smart DustBPN814BPN814 WebsiteUHF Capacitive-Gap Transduced Resonators With High Cx/CoClark T.-C. Nguyen
62Wireless, RF & Smart DustBPN701BPN701 WebsiteBridged Micromechanical FiltersClark T.-C. Nguyen
63Wireless, RF & Smart DustBPN744BPN744 WebsiteSelf-Destructing SiliconKristofer S.J. Pister, Michel M. Maharbiz
64Wireless, RF & Smart DustBPN803BPN803 WebsiteSingle Chip MoteKristofer S.J. Pister, Ali M. Niknejad
65Physical Sensors & DevicesBPN826BPN826 WebsiteAutonomous Flying MicrorobotsKristofer S. J. Pister
66Wireless, RF & Smart DustBPN735BPN735 WebsiteWalking Silicon MicrorobotsKristofer S. J. Pister
67Physical Sensors & DevicesBPN802BPN802 WebsiteElectret-Enabled Energy Harvesters for Use Near Current-Carrying ConductorsRichard M. White, Paul K. Wright
68Physical Sensors & DevicesBPN801BPN801 WebsiteEmergency Power-Line Energy HarvestersRichard M. White, Paul K. Wright
69Physical Sensors & DevicesBPN838BPN838 WebsiteDosimetry Dust: An Implantable Dosimeter for Proton Beam Therapy Treatment of Ocular Melanomas New ProjectMichel Maharbiz, Mekhail Anwar
70Wireless, RF & Smart DustBPN848BPN848 WebsiteHighly Integrated, Compact Wearable Ultrasound System for Chronic Biosensing New ProjectMichel Maharbiz, Bernhard Boser
71Physical Sensors & DevicesBPN731BPN731 WebsiteFlexible Electrodes and Insertion Machine for Stable, Minimally-Invasive Neural RecordingMichel M. Maharbiz, Philip N. Sabes
72Package, Process & MicroassemblyBPN823BPN823 WebsiteAutomated System for Assembling a High-Density Microwire Neural Recording ArrayMichel M. Maharbiz, Kristofer S.J. Pister
73BioMEMSBPN573BPN573 WebsiteCarbon Fiber Microelectrode Array for Chronic Stimulation and RecordingMichel M. Maharbiz, Kristofer S.J. Pister
74Wireless, RF & Smart DustBPN844BPN844 WebsiteWireless Sub-Millimeter Temperature Sensor for Continuous Temperature Monitoring in Tissue New ProjectMichel M. Maharbiz
75BioMEMSBPN816BPN816 WebsiteCytokine Fast DetectionMichel M. Maharbiz
76BioMEMSBPN771BPN771 WebsiteSilicon Carbide ECoGs for Chronic Implants in Brain-Machine InterfacesMichel M. Maharbiz
77BioMEMSBPN795BPN795 WebsiteAn Implantable Micro-Sensor for Cancer SurveillanceMichel M. Maharbiz
78BioMEMSBPN718BPN718 WebsiteDirect Electron-Mediated Control of Hybrid Multi-Cellular RobotsMichel M. Maharbiz
79BioMEMSBPN716BPN716 WebsiteUltrasonic Wireless Implants for Neuro-modulationMichel M. Maharbiz
80Physical Sensors & DevicesBPN808BPN808 WebsiteAcoustic Detection of Neural ActivityMichel M. Maharbiz
81Physical Sensors & DevicesBPN765BPN765 WebsiteFull-Field Strain Sensor for Hernia Mesh RepairsMichel M. Maharbiz
82Physical Sensors & DevicesBPN714BPN714 WebsiteImpedance Sensing Device to Monitor Pressure UlcersMichel M. Maharbiz
83Physical Sensors & DevicesBPN780BPN780 WebsiteImpedance Spectroscopy to Monitor Fracture HealingMichel M. Maharbiz

Project Abstracts

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Table of Projects
Wireless, RF & Smart Dust
Project IDBPN840 New Project
Project Title W-band Additive Vacuum Electronics
Status New
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 electro-chemical and micro-fluidic 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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Microfluidics
Project IDBPN846 New Project
Project Title 3D Printed Biomedical and Diagnostic Systems
Status New
Funding Source BSAC Member Fees
Keywords
Researchers Eric C. Sweet, Joshua Chen, Ilbey Karakurt
Abstract Every year, more than twenty thousand people in the United States die from antibiotic-resistant bacterial infections. Despite increasing rates of antibiotic resistance, little clinical research is being performed into the discovery of new drugs; instead, a commonly used method to combat antibiotic resistance is combination therapy, where various antibiotics are combined into a “drug cocktail” to be simultaneously administered to the patient. However, biomedical research into the interactions of three or more antibiotics is fairly limited, a result of the critical functional-limitation of standard BioMEMS analytical devices (e.g., two-dimensional PDMS microfluidic chips fabricated via soft lithography) that such monolithic structures can only produce gradients of two fluidic inputs at a time. Furthermore, the biomedical community lacks a simple and accessible method of determining the minimum inhibitory concentration (MIC) of a single antibiotic where the gold standard is still manual labor-intensive pipetting, dilutions, and agar plates. For this project, we present a novel micro-scale 3D printed microfluidic concentration gradient generator (CGG) that produces a symmetric concentration gradient between three fluidic inputs, which we used to determine the interactions of various combinations of three commonly clinically administered antibiotics (Nitrofurantoin, Tetracycline and Trimethoprim), as well as the MIC value for each individual antibiotic, on ampicillin- resistant E. Coli. Bacteria. Our singular device could be used in a clinical setting, when attempting to treat a known or unknown antibiotic-resistant strain, to decrease the analysis time and required volume of antibiotics to perform a determination of the interactions of multiple antibiotics simultaneously, as well as to analyze the MIC value of each antibiotic, which could set a significant clinical precedent resulting in faster and more effective treatment of new infections and potentially a greater number of patient lives saved. Furthermore, our three-flow CGG could increase the efficacy and speed of experiments in other areas in biomedical research where concentration gradients of reagents are relevant, such as stem cell research.
Contact Information ericsweet@berkeley.edu, ilbeykarakurt@berkeley.edu, josh.cl.chen@berkeley.edu
Advisor Liwei Lin

 
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Microfluidics
Project IDBPN774
Project Title 3D Printed Integrated Microfluidics: 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
Researchers Eric Sweet, Ilbey Karakurt, Rudra Mehta, Ryan Jew
Abstract Low-powered microfluidic systems have been demonstrated in a variety of point-of-care biomedical diagnostic applications; however, the potential for the widespread commercial applicability of this technology, the requirement for being portable, disposable and inexpensive, is greatly hindered by the nearly-ubiquitous need for bulky and expensive externally-powered pressure sources needed to pump fluids through such devices. Furthermore, as advanced additive manufacturing techniques such as micro/nano-scale 3D printing are becoming more widely used in BioMEMS manufacturing, conventional soft-lithography fabrication approaches are becoming comparatively more costly, time consuming and labor intensive. To overcome these critical limitations of conventional microfluidics, for this project we propose a low-cost microfluidic one-way pumping and mixing system powered solely by the operator’s finger fabricated via micro-scale 3D printing. The three-dimensional geometric complexity permitted only by additive manufacturing processes allows for the construction of fully-integrated three-dimensional micro-scale fluidic control and actuation elements (i.e. fluidic diodes and thin membrane-enclosed interconnected balloon cavities and capacitor- like fluidic actuation source). We demonstrate a 3D printed one-way microfluidic pump, allowing the user to pump fluid at upwards of 150 micro-Liters/minute, with flow rate correlating to the pumping frequency. Furthermore, we will demonstrate the application of two integrated one-way pumps as a 3D printed microfluidic mixer capable of rapid pulsatile mixing of two fluids, powered by a singular shared finger-powered pump. Our finger-powered 3D printed microfluidic devices have established an alternative to conventional externally-powered microfluidics, and upon further development, such designs could prove critical tools in resolving the foremost commercial limitations of conventional microfluidic point-of-care diagnostic devices.
Contact Information ericsweet2@gmail.com, ilbeykarakurt@berkeley.edu, Rudra.Mehta@berkeley.edu, rjew@berkeley.edu
Advisor Liwei Lin

 
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Micropower
Project IDBPN742
Project Title 3D Carbon-Based Materials for Electrochemical Applications
Status Continuing
Funding Source BSAC Member Fees
Keywords
Researchers Xining Zang, Minsong Wei
Abstract We design and develop both the electrode and electrolyte to address a new energy storage system with high energy and high power density. TiS¬2 is the cheapest and lightest sulfate in the transition metal di-chalcogenide (TMDC) family, with the highest energy storage potential as lithium-ion battery anode material. In this paper, TiN coated onto carbon nanotube (CNT) by atomic layer deposition is converted to TiS2 annealing in sulfur vapor flow. Combining the high surface area and high conductivity induced by CNT and the interlayer ion storage of TiS2, the hybrid material results in a specific capacitance of ~170F/cm3 (roughly 170F/g). We introduce the salt lithium bis(trifluoromethane sulfonyl)imide (LiTFSI) which has only been applied in Li+ battery before in aqueous supercapacitors, and prove a working voltage of 3 V which not only breaks the water splitting limit of 1.23 V but also power the energy density up to 212 Wh/kg. Cyclic voltammetry test of TiS2/CNT LiTFSI cell shows the character of supercapacitors, while TiS2 intercalation with Li+ introduce battery character instead of redox reaction in pseduocapacitors. Addressing this hybrid supercapacitor-battery, highest power density and energy density based on aqueous electrolyte. LiTFSI, the water in salt electrolyte is also dissolve in PVA/H2O gel to make semi solid state electrolyte for device assembly. Flexible supercapacitors-battery based on the LiTFSI with symmetric double electrode performs at 2.5 V with a high device projection capacitance of ~ 60mF/cm2.
Contact Information xining.zang.me@berkeley.edu
Advisor Liwei Lin

 
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Micropower
Project IDBPN782
Project Title Flexible Micro Supercapacitors
Status Continuing
Funding Source Army/ARL
Keywords Flexible supercapacitor, carbon fiber, strain sensor, nanofiber
Researchers Caiwei Shen, Weihua Cai, Yingxi Xie
Abstract The integration of flexible electronics into every day clothing could find intriguing applications in medical care and consumer electronics. Flexible power devices are crucial to make such systems successful. Here we demonstrate high-performance coaxial fiber supercapacitors with the size of a single cotton fiber as promising building blocks for wearable power devices. Moreover, free-standing “supercapacitor fabrics” in the scale of square centimeters have been successfully woven.
Contact Information shencw10@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 stationary power 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. Silicon has demonstrated promising capabilities as photocatalysts due to its high visible light absorption, low cost, and high abundance. This project aims to improve the performance of silicon for water splitting by developing new high- surface area silicon photoelectrodes using chemical vapor deposition silicon.
Contact Information kao@berkeley.edu
Advisor Liwei Lin

 
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NanoTechnology: Materials, Processes & Devices
Project IDBPN800
Project Title Solution Processed Transparent Electronics
Status Continuing
Funding Source BSAC Member Fees
Keywords
Researchers Hyun Sung Park
Abstract Recently there has been growing interest in transparent conductive oxides(TCOs) and oxide semiconductors, they are key components for future transparent electronics devices. But there are needs for finding new TCOs and oxide semiconductors because the Indium and Galium are expensive rare earth material and the price is still increasing. Conventional vacuum based process is a also problem for large scale and complicated geometry devices. In this project, I introduced new TCO material(ATO) for the future transparent electronics devices by using solution process.
Contact Information hs23.park@gmail.com
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, matallization
Researchers Hyung-Seok Jang
Abstract Electro-Hydrodynamic (EHD) Printing based direct write method has been demonstrated that the efficient fabrication process for the fast-response and super-thin silver (Ag) passive temperature sensor. For the direct write Ag passive temperature sensor, biological polymer was applied for efficient Ag nanostructure formation, and the EHD Printer directly eject and deposit this Ag precursor ink on the substrate. During annealing process this Ag passive sensor rapidly produce the 2D nanoparticles from the air/water interface and directly sintered to Ag thin film patterns in 200oC. This direct write silver passive temperature sensor would be applicable in several applications such as displays, sensors, solar cells and several other electronic devices.
Contact Information hyungseok1024@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, Yong Cui, Takeshi Hayasaka, Kaiming Hu, Xiaoqian Li
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-invasively. 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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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
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
Advisor Liwei Lin

 
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BioMEMS
Project IDBPN685
Project Title Real-Time Intraoperative Fluorescent 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 grids patterned in the metal interconnect of a standard CMOS process.
Contact Information epp@berkeley.edu, anwarme@radonc.ucsf.edu
Advisor Bernhard E. Boser, Mekhail Anwar

 
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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
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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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, Sujay Desai, Matin Amani, Seth Fortuna
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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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 Tae Joon Seok
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 tjseok@eecs.berkeley.edu
Advisor Ming C. Wu

 
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NanoPlasmonics, Microphotonics & Imaging
Project IDBPN721
Project Title Electronic-Photonic Heterogeneous Integration (EPHI) for High Resolution FMCW LIDAR
Status Continuing
Funding Source DARPA
Keywords optical phase-locked loop, silicon photonics, 3D integration, MEMS, CMOS, VCSEL, HCG, PIC, FMCW LIDAR,
Researchers Phillip A.M. Sandborn
Abstract Range-finding sensors have applications that span several industries and markets, from metrology to robotic control. In order to penetrate large consumer markets such as 3D imaging for smart-phones or automotive 3D vision, the size and cost of laser detection and ranging (LIDAR) sensors must be reduced by an order of magnitude. By leveraging emerging electronic-photonic integration technology, compact LIDAR sensors with reduction in size/cost can be constructed. We demonstrate the integration of passive Si photonic circuits and CMOS electronic circuits to create a frequency-modulated continuous-wave laser detection and ranging (FMCW LIDAR) source using this technology. Results have shown that electronic-photonic 3D integration of optoelectronic components can greatly improve the performance of FMCW LADAR sources. We demonstrate an FMCW LADAR with 4-micron ranging precision.
Contact Information sandborn@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, Yung-Hsiang Lin
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 10-19 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, yhlin@berkeley.edu
Advisor Ming C. Wu

 
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NanoPlasmonics, Microphotonics & Imaging
Project IDBPN788
Project Title Optical Phased Array for LIDAR
Status Continuing
Funding Source Industry
Keywords Lidar, Optical MEMS, Beamsteering
Researchers Youmin Wang
Abstract We have previously demonstrated the development of an Optical Phased Array (OPA) micromechanical system (MEMS) used for beam steering, which shows great advantages over previous mechanisms such as opto-mechanical, acoustooptical (AO) or electro-optical (EO). 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, while competing technologies (AO, EO) utilize devices that while small in size, 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.
Contact Information youmin.wang@berkeley.edu, wu@eecs.berkeley.edu
Advisor Ming C. Wu

 
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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
Abstract Coupling an optical antenna to a nanoscale light emitter has been shown to increase the spontaneous emission rate by compensating for the large size mismatch between the emitter and emission wavelength. This spontaneous emission rate enhancement has been predicted to be as large as several orders of magnitude, easily surpassing the stimulated emission rate and enabling high direct modulation bandwidths. The aim of this project is to utilize this concept to demonstrate a directly modulated nanoscale semiconductor light emitting diode (nanoLED) with modulation speeds in excess of 10s of GHz, exceeding the bandwidth of semiconductor lasers. Unlike lasers, such nanoLEDs are also inherently low-power and do not require minimum threshold current density for operation and are therefore a promising light generating source for use, for example, in on-chip communication.
Contact Information fortuna@eecs.berkeley.edu
Advisor Ming C. Wu

 
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Microfluidics
Project IDBPN552
Project Title Light-Actuated Digital Microfluidics (Optoelectrowetting)
Status Continuing
Funding Source BSAC Member Fees
Keywords Digital Microfluidics, Droplet Microfluidics, Electrowetting, Optoelectrowetting, EWOD, Optofluidics
Researchers Jodi Loo
Abstract The ability to quickly perform large numbers of chemical and biological reactions in parallel using low reagent volumes is a field well addressed by droplet-based digital microfluidics. Compared to continuous flow-based techniques, digital microfluidics offers the added advantages such as individual sample addressing and reagent isolation. We are developing a Light- Actuated Digital Microfluidics device (also known as optoelectrowetting) that optically manipulates nano- to micro-liter scale aqueous droplets on the device surface. The device possesses many advantages including ease of fabrication and the ability for real-time, reconfigurable, large-scale droplets control (simply by altering the low-intensity projected light pattern). We hope to develop Light-Actuated Digital Microfluidics into a powerful platform for lab-on-a-chip (LOC) applications.
Contact Information jodiloo@eecs.berkeley.edu
Advisor Ming C. Wu

 
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NanoPlasmonics, Microphotonics & Imaging
Project IDBPN836 New Project
Project Title Nanocrescent antenna for nanofocusing of excitation radiation and concentrate upconversion emission
Status New
Funding Source Foundation
Keywords upconversion, plasmonics, Lanthanide, nanocrescent, antenna
Researchers Doyeon Bang
Abstract Frequency upconversion activated with Lanthanide have attracted in various real-world applications, because it is far more simple and effective than traditional nonlinear susceptibility based frequency upconversion, such as second harmonic generation. However, quantum yield of frequency upconversion of Lanthanide-based upconversion nanoparticle remain inefficient for practical applications and spatial control of upconverted emission is not yet developed. To overcome this limitation, we developed asymmetric hetero-plasmonic nanoparticles (AHPNs) consist of plasmonic antenna in nanocrescent shape on the Lanthanide-based upconversion nanoparticle for nano-focusing of excitation laser to the upconversion nanoparticle and concentrate upconverted photon emission into a certain direction. AHPNs were fabricated by high-angle deposition (60¨¬) of Au on the isolated upconversion nanoparticles supported by nano- pillar then moved to refractive-index matched substrate for orientation dependent upconversion luminescence analysis in single- nanoparticle scale. We analyzed shape dependent nano-focusing efficiency of nanocrescent antenna by modulating deposition angle. Concentration of upconverted photon emission toward the tip of nanocrescent antenna was simulated by asymmetric far-field radiation pattern of dipole in the nanocrescent antenna and demonstrated by the orientation dependent upconverted photon emission of AHPNs. This finding provide a new way to improve frequency upconversion using an antenna, which locally increase the excitation laser and concentrate the radiation power to certain direction.
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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Microfluidics
Project IDBPN824
Project Title Investigation of Dengue Infection’s Neurological Complications via a Comprehensive in-vitro Brain Model
Status New
Funding Source PCARI
Keywords Dengue fever, Neurological Complications, microfluidics
Researchers SoonGweon Hong, Minsun Song
Abstract Dengue fever is one of global health concerns as two fifth of world population are considered to expose to the infection risk and 20K patients results in death per year. Even after successful recovery from the febrile disease, it often causes secondary neurological complications including encephalopathy, residual brain damage and seizures. However, unclear etiological details of neurological disorders still inhibit to uncover suitable treatments of the complications. Herein, we develop an in-vitro brain model for the comprehensive systematic analysis of neurological complications due to of the Dengue infections. Our new minibrains-on- a-chip concept will allow to mature brain tissue mimicking in-vivo tissue complex in an interstitial fluidic dynamics and to monitor electrophysiological phenotypes in an in-situ manner. By administrating various etiological factors found in dengue virus (DENV) infection along with the dynamic flow, we will be able to address phenotypic connections of individual etiological factors. Our integrated in-vitro brain model analysis platform for Dengue infections will potentially provide a diagnostic and therapeutic frame for various levels of neurological disease associated with DENV infection.
Contact Information gweon1@berkeley.edu
Advisor Luke P. Lee

 
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BioMEMS
Project IDBPN804
Project Title A Rapid, Integrated Molecular Diagnostic for Gram-Negative Pathogen Detection and Identification Based on Antibody-Based Capture and Photonic PCR
Status Continuing
Funding Source NIH
Keywords
Researchers Byungrae Cho, Jun Ho Son, Sang Hun Lee
Abstract The fast and precise detection and identification of pathogens has become significantly important in medicine, food safety, public health, and security. However, the conventional testing (bacteria cultures with several antibiotics for susceptibility test) needs one to four days to acquire the result. Here, we develop an integrated molecular diagnostic system that combines sample preparation, pathogen lysis, and genetic detection to identify pathogens within one hour. Bacteria in relatively large-volume sample (3-5 mL) continuously passing through a fluidic channel are captured and identified by antibodies on the gold-coated nanopore membranes within 30 min. Gold - coated membranes can easily raise the temperature beyond 70 degrees Centigrade under LED light emission enabling rapid pathogen lysis. Combining with temperature control and photonic system, PCR can be executed for genetic detection of pathogen within 5 min. We expect that this integrated molecular diagnostic system will provide rapid diagnosis of pathogen infection and contribute to precision medicine.
Contact Information brcho@berkeley.edu, jhson78@berkeley.edu, sanghun.lee@berkeley.edu
Advisor Luke P. Lee

 
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Microfluidics
Project IDBPN730
Project Title Microfluidic Blood Plasma Separation for Point-of-Care Diagnostics
Status Continuing
Funding Source PCARI
Keywords Microfluidic, Blood plasma separation, Point-of-care, PCR
Researchers Jun Ho Son, Sang Hun Lee, ByungRae Cho
Abstract Microfluidic lab-on-a-chip (LOC) device for point-of-care (POC) diagnostics have been widely developed for the rapid detection of infectious diseases such as HIV, TB and Malaria. Blood plasma separation is an initial step for most blood-based diagnostics. Although, centrifuge method is the classical bench-top technique, it is time and labor intensive, and therefore, automation and integration of blood plasma separation in the LOC device is ideal for POC diagnostics. Here, we propose a novel microfluidic blood plasma separation device for POC diagnostics. A membrane filter for filtration was positioned on top of a vertical up-flow channel (filter-in-top configuration) to reduce clogging of red blood cells (RBCs) by gravity-assisted cells sedimentation to prevent hemolysis of RBCs. As a result, separated plasma volume was increased about 4-fold (2.4 µL plasma after 20 min with human blood) and hemoglobin concentration in separated plasma was decreased about 90 % due to the prevention of RBCs hemolysis in comparison to a filter-in-bottom configuration. On-chip plasma contains ~90 % of protein and ~100 % of nucleic acids compared to off-chip centrifuged plasma, showing comparable target molecules recovery. This investigation will lead to a simple and reliable blood plasma separation device that can be utilized by individuals with minimal training in resource-limited environments for POC diagnostics.
Contact Information jhson78@berkeley.edu, sanghun.lee@berkeley.edu, brcho@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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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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Microfluidics
Project IDBPN839 New Project
Project Title Flow Control in Plastic Microfluidic Devices using Thermosensitive Gels
Status New
Funding Source BSAC Member Fees
Keywords
Researchers Karthik Prasad, 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 IDBPN847 New Project
Project Title A 3D Printed Microfluidic-Based Blood Filtration Device Examines the Effect of Blood Components in Aging Process
Status New
Funding Source BSAC Member Fees
Keywords
Researchers Kiana Aran, Daniel Park
Abstract Studies on blood parabiosis between young and old mice have shown reversals in the progression of aging. However, the definitive cellular elements in young mice that advance rejuvenation in old mice are yet to be identified. The goal of this project is to determine the specific blood component in young mice responsible for rejuvenation in old mice. This project focuses on designing a microfluidic-based blood exchange device capable of continuously separating and exchanging different type of blood components during blood transfusion between small animals to help identify the blood components responsible for rejuvenation.
Contact Information k.aran@berkeley.edu
Advisor Dorian Liepmann

 
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Microfluidics
Project IDBPN711
Project Title Point-of-Care System for Quantitative Measurements of Blood Analytes Using Graphene-Based Sensors
Status Continuing
Funding Source NSF
Keywords Biosensor, healthcare, graphene, microfluidics
Researchers Kiana Aran, Kathryn Fink
Abstract Serum glucose, cholesterol, triglyceride and HbA1C monitoring are all valuable tools in the health management of the aging population, especially given the increase in diabetes and cardiovascular diseases. Even for glucose monitoring, the challenges obtaining sufficiently accurate and reliable measurements are so significant that the FDA is contemplating more stringent standards. Guido Freckmann, et al., J. Diabetes Sci. Tech. 6, 1060-1075, 2012, have compared 43 blood glucose self- monitoring systems. Out of this, 34 systems were completely assessed and 27 (79.4%) systems fulfilled the minimal accuracy requirements and only 18 (52.9%) of 34 systems fulfilled the requirements of the proposed tighter criteria in the current standards draft. None of them meet the even more stringent requirement of ISO 2012 and FDA. Because inaccurate systems bear the risk of false therapeutic decisions and rising health care costs, there is an urgent need for significantly enhanced BG monitoring systems for PC applications. POC tests for other biomedically important analytes are generally even less accurate. The overall goal of the proposed research is to develop new sensor platforms that will provide increased sensitivity and accuracy in point-of-care situations. This is a joint project with Harvard Medical School and Vanderbilt University.
Contact Information liepmann@berkeley.edu, k.aran@berkeley.edu, kdfink@berkeley.edu
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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Microfluidics
Project IDBPN732
Project Title The Role of Erythrocyte Size and Shape in Microchannel Fluid Dynamics
Status Completed
Funding Source Fellowship
Keywords
Researchers Kathryn Fink, Karthik Prasad
Abstract The unique properties of blood flow in microchannels has been studied for nearly a century; much of the observed blood-specific dynamics is attributed to the biconcave shape of red blood cells. However, for almost twice as long biologists have observed and characterized the differences in size and shape of red blood cells among vertebrates. With a few exceptions, mammals share the denucleated biconcave shape of erythrocytes but vary in size; oviparous vertebrates have nucleated ovoid red blood cells with size variations of a full order of magnitude. We utilize micro-PIV and pressure drop measurements to analyze blood flow of vertebrate species in microchannels, with a focus on understanding how cell size and shape alter the cell-free layer and velocity profile of whole blood. The results offer insight into the Fahraeus-Lindqvist effect and the selection of animal blood for the design and evaluation of biological microfluidic devices.
Contact Information kdfink@berkeley.edu, liepmann@berkeley.edu
Advisor Dorian Liepmann

 
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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 Jeronimo Segovia-Fernandez, Scott Block, Soner Sonmezoglu
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 jsegoviaf@ucdavis.edu, stblock@ucdavis.edu, ssonmezoglu@ucdavis.edu, dahorsley@ucdavis.edu, ramirtha
Advisor David A. Horsley, Rajeevan Amirtharajah

 
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Physical Sensors & Devices
Project IDBPN849 New Project
Project Title Large-amplitude PZT PMUTs
Status New
Funding Source BSAC Member Fees
Keywords PMUT, piezoelectric, PZT
Researchers Yuri Kusano
Abstract Thin film lead zirconate titanate (PZT) has been widely used as a piezoelectric material in MEMS devices. We design and characterize PZT PMUTs with a large displacement amplitude by operating in air.
Contact Information ykusano@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, Stephanie Fung, 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. The resulting 110X56 PMUT array, composed of 30um X 43um rectangular PMUTs achieved a 51.7% fill-factor, three times greater than that of the previous design. Together with the custom CMOS ASIC, the sensor chieves 2 uV/Pa sensitivity, 19 kPa peak-to-peak pressure output, 75 um lateral resolution, and 150 um axial resolution in a 4.6 mm X 3.2 mm image.
Contact Information joy.jiang@berkeley.edu, dahorsley@ucdavis.edu
Advisor David A. Horsley

 
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Physical Sensors & Devices
Project IDBPN785
Project Title Scandium-doped AlN for MEMS
Status Continuing
Funding Source BSAC Member Fees
Keywords Piezoelectric, MEMS, AlN, ScAlN, Thin films
Researchers Qi Wang
Abstract The goal of this project is to design, fabricate and characterize novel MEMS devices based on scandium-doped 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 dahorsley@ucdavis.edu, qixwang@ucdavis.edu
Advisor David A. Horsley

 
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Physical Sensors & Devices
Project IDBPN599
Project Title MEMS Electronic Compass: Three-Axis Magnetometer
Status Continuing
Funding Source Federal
Keywords
Researchers Soner Sonmezoglu
Abstract High sensitivity, low cost, low power, and direct integration with MEMS accelerometers and gyroscopes make the MEMS magnetic sensor a very attractive option in consumer electronic devices. The goal of this project is to develop a low-power three axis MEMS magnetic sensor suitable for use as an electronic compass in smart phones and portable electronics. Our objective is to achieve a resolution of 200 nT/rt-Hz and power consumption of 1 mW/axis with DC power supply of 1.8 V. Although past devices designed by our group have demonstrated that our resolution goal is reachable, these devices suffered from dc offset larger than Earth's field and required an external programmable oscillator for operation. Here, we aim to reduce offset by two orders of magnitude for improving the long-term stability of the magnetic sensor and to develop self-oscillation loops to excite the sensor either at resonance or off-resonance.
Contact Information ssonmezoglu@ucdavis.edu, dahorsley@ucdavis.edu
Advisor David A. Horsley

 
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Physical Sensors & Devices
Project IDBPN603
Project Title Micro Rate-Integrating Gyroscope
Status Continuing
Funding Source DARPA
Keywords MEMS, Rate Integrating Gyroscope, Controls
Researchers Parsa Taheri-Tehrani
Abstract The goal of this project is to realize a micro rate-integrating gyroscope that produces an output signal proportional to rotation angle rather than rotation rate. This device would eliminate the need of integrating the gyroscope's rate output to obtain the angle. Gyroscope resonators have at least two resonant modes that can be coupled by Coriolis force. Difference in damping coefficients and stiffness of the resonant modes of the MEMS resonator known as anisodamping and anisoelasticity are main sources of error in RIG. So realizing a micro rate-integrating gyroscope can be achieved by having highly symmetrical gyroscopes with extremely close frequency matching (delta f < 1 Hz) and high time constant (high quality factor). Control algorithms should be developed to eliminate the residual anisodamping and anisoelasticity errors.
Contact Information dahorsley@ucdavis.edu, ptaheri@ucdavis.edu
Advisor David A. Horsley

 
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Physical Sensors & Devices
Project IDBPN812
Project Title Improving Micro-Oscillators Performance By Exploiting Nonlinearity
Status Continuing
Funding Source BSAC Member Fees
Keywords micro-oscillator. nonlinearity. multi-tone actuation. mode coupling.
Researchers Martial Defoort
Abstract Due to their small size, micro-sensors experience complex phenomena including the emergence of nonlinearities, affecting the intrinsic properties of the system and commonly known to reduce its performance. In the case of micro-resonators, while larger displacement typically leads to lower SNR, it also increases the nonlinearity of the system, altering both frequencies and quality factors which in turn decrease stability and thus performance. However, a careful control of these nonlinearities opens the way for new implementation schemes and improved stability in micro-sensors, such as phase fluctuations reduction, frequency control and in-situ amplification schemes. This project involves both experimental and theoretical approaches to study the benefits of nonlinearity for micro-oscillators applications, including frequency- reference, sensing, and energy transfer.
Contact Information mjdefoort@ucdavis.edu, dahorsley@ucdavis.edu
Advisor David A. Horsley

 
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NanoTechnology: Materials, Processes & Devices
Project IDBPN834 New Project
Project Title Direct Formation of Pore-Controllable Mesoporous SnO2 for Gas Sensing Applications
Status New
Funding Source Industry
Keywords amphiphilic graft copolymer, mesoporous SnO2, sol-gel, microheater, gas sensor
Researchers Won Seok Chi
Abstract Amphiphilic graft copolymer self-assembly provides an effective method to create mesoporous structures that can act as templates for the synthesis of inorganic materials with controlled morphology. In this project, we are using PVC-g-POEM graft copolymer as a template for mesoporous SnO2 fabrication directly onto a microheater platform for gas sensing applications. The sol-gel solution composed of PVC-g-POEM and SnO2 precursor is drop casted onto microheater-based sensor. By proper control of the temperature profile, the polymer template is removed, yielding mesoporous SnO2 structure. The mesoporous SnO2 structures are controllable by using different self-assembly of sol-gel solution, providing various pore size and surface area formation. This approach allows us to investigate and optimize the effects of different mesoporous SnO2 structures towards sensing various gaseous species of interest.
Contact Information lucas38c@berkeley.edu
Advisor Roya Maboudian, Carlo Carraro

 
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NanoTechnology: Materials, Processes & Devices
Project IDBPN843 New Project
Project Title Non-enzymatic Electrochemical Sensors Based on Wearable Carbon Textile
Status New
Funding Source NSF
Keywords
Researchers Sinem Ortaboy, Hu Long
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 the promising materials due to their good conductivity, low-cost, biocompatibility and stability even in the harsh environment conditions. In this study, flexible carbon-based textile incorporating electroactive species will be used as the electrode for electrochemical sensor and biosensor applications.
Contact Information sinemortaboy@berkeley.edu, longhu@berkeley.edu
Advisor Roya Maboudian, Carlo Carraro

 
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NanoTechnology: Materials, Processes & Devices
Project IDBPN835 New Project
Project Title Silicon Carbide Passivated Electrode for Thermionic Energy Conversion
Status New
Funding Source Federal
Keywords Silicon Carbide, Tungsten, Thermionic Emission, LPCVD, High-Temperature
Researchers Steven R. DelaCruz, Chuan-Pei Lee, Ping Cheng
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), creating 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 recently 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, chuanpeilee@berkeley.edu, carraro@berkeley.edu, pchen
Advisor Roya Maboudian, Carlo Carraro

 
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Table of Projects
NanoTechnology: Materials, Processes & Devices
Project IDBPN837 New Project
Project Title Metal oxide-coated carbonized-silicon nanowires as high-performance micro-supercapacitor
Status New
Funding Source BSAC Member Fees
Keywords
Researchers Yuan Gao, Sinem Ortaboy, Chuan-Pei Lee
Abstract With the rapid development of modern digital technology, micro-supercapacitors show tremendous potential to complement or replace conventional electrolytic capacitors and batteries due to their small dimension, high power density, high electrochemical efficiency and long cyclic life. In particular, porous silicon nanowires (PSiNWs) and their derivatives have attracted great attention owing to their high surface areas and ease of integration with the microfabrication methodology. In this project, we are developing a novel metal oxide-coated carbonized PSiNWs electrodes for micro-supercapacitor applications and will present our synthesis and chacterization efforts.
Contact Information gaoyuan1988@berkeley.edu, yuangao_1988@hotmail.com
Advisor Roya Maboudian, Carlo Carraro

 
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Table of Projects
Physical Sensors & Devices
Project IDBPN842 New Project
Project Title Conductometric gas sensing behavior of WS2 aerogel
Status New
Funding Source NSF
Keywords Tungsten Disulfide, Aerogel, Gas Sensor
Researchers Wenjun Yan
Abstract The gas sensing characteristics of a high surface area tungsten disulfide (WS2) aerogel are investigated. Gas sensors are fabricated by integrating a low-density WS2 aerogel onto a low power polysilicon microheater platform to provide control over the operating temperature. The response of the WS2 aerogel-based sensors to NO2, O2, and H2 is investigated with the sensing characteristics indicating p-type behavior. The optimum sensing temperature is found to be about 250 ℃;, when considering sensitivity, power consumption and response time. The role of O2 in H2 and NO2 sensing is probed and O2 is found to be helpful for enhancing the sensitivity and recovery of the sensor to H2.
Contact Information wenjunyan@berkeley.edu, maboudia@berkeley.edu
Advisor Roya Maboudian, Carlo Carraro

 
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Table of Projects
NanoTechnology: Materials, Processes & Devices
Project IDBPN827
Project Title Metal Oxide-decorated Silicon Carbide Nanowires Electrode for The Applications on Electrochemical Energy Storage
Status New
Funding Source NSF
Keywords Nanowires, Silicon Carbide, Supercapacitor, Water Splitting
Researchers Chuan-Pei Lee, Steven DelaCruz
Abstract Since the discovery of electricity, we are looking for promising methods to store that energy for use on demand. In the energy storage industry, electrochemical water splitting is a well-established technology to convert electricity into chemical energy, addressing the issues of effective storage and transport. On the other hand, electrochemical capacitors, namely supercapacitors, have also attracted much attention for electrical energy storage because of their feature of both high power density and energy density. In this work, we are developing processes for the synthesis of metal oxide/silicon carbide nanowires composite electrodes and investigating their potential for the applications in water splitting and supercapacitor systems.
Contact Information chuanpeilee@berkeley.edu, maboudia@berkeley.edu
Advisor Roya Maboudian, Carlo Carraro

 
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NanoTechnology: Materials, Processes & Devices
Project IDBPN790
Project Title Low Power Microheater-Based Platform for Gas Sensing
Status Continuing
Funding Source Industry
Keywords
Researchers Hu Long, Leslie Chan
Abstract Detection of toxic air pollutants such as carbon monoxide (CO), nitrogen dioxide (NO2), and formaldehyde is of critical importance to public health, industry, and the environment. Since these toxic gases are commonly generated from combustion or automotive emissions, there is a need for high-performance sensors that are capable of detecting low concentrations of toxic gases in air rapidly, accurately, and reliably. This work reports the integration of nanostructured materials on a microheater-based sensing platform to achieve fast, sensitive, selective, and stable gas sensing. We have developed a sensitive CO sensor by in situ synthesis of porous SnO2 films on a low power microheater. The sensor can detect 10 ppm CO with fast response and recovery times at low temperature. By integrating 3D plasma-treated MoS2 aerogels on the low power microheater, the sensor exhibits a detection limit of 50 ppb NO2 at both room temperature (0.1 mW power consumption) and 200 °C (~ 4 mW power consumption) while showing negligible response to CO and H2. Using hierarchical ZnCo2O4 microstructures on the low power microheater, the sensor can detect 3 ppb formaldehyde with good selectivity. Current work is focused on better understanding the sensing behavior of these sensors.
Contact Information longhu@berkeley.edu,
Advisor Roya Maboudian, Carlo Carraro

 
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Table of Projects
NanoTechnology: Materials, Processes & Devices
Project IDBPN813
Project Title Novel Hierarchical Metal Oxide Nanostructures for Conductometric Gas Sensing
Status Continuing
Funding Source Industry
Keywords
Researchers Ameya Rao, Hu Long
Abstract Metal oxide semiconductors have been extensively studied as sensing materials for conductometric gas sensors. Although porous hierarchical nanostructures (e.g. hollow spheres, tubes) of some metal oxides (e.g. tin oxide) have been reported to have high sensitivity and response/recovery speed, there has been no investigation into the combination of the hierarchical structures of multiple oxides. Such a combination (e.g. multiple concentric porous shells of different metal oxides) could show improved sensing performance compared to structures of just one material, including increased selectivity, in which many single metal oxides are poor. We are developing a simple and reproducible fabrication method for these novel nanostructures, including their controllable integration onto a low power microheater platform, which may be used in numerous combinations of different materials for a wide range of applications.
Contact Information ameyarao@berkeley.edu
Advisor Roya Maboudian

 
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NanoTechnology: Materials, Processes & Devices
Project IDBPN832 New Project
Project Title Gold-Mediated Exfoliation of Ultralarge Optoelectronically-Perfect Monolayers
Status New
Funding Source Federal
Keywords TMDC, gold exfoliation, layered materials, MoS2, large-area monolayer
Researchers Sujay B. Desai, Mark Hettick
Abstract Gold-mediated exfoliation of ultralarge optoelectronically perfect monolayers with lateral dimensions up to ≈500 μm is reported. Electrical, optical, and X-ray photo­electron spectroscopy characterization show that the quality of the gold-exfoliated flakes is similar to that of tape- exfoliated flakes. Large-area flakes allow manufacturing of large-area mono­layer transition metal dichalcogenide electronics. Further work involves automating and mechanizing the transfer process for more controlled exfoliation and transfer of TMDC monolayers onto desired substrates.
Contact Information sujaydesai@eecs.berkeley.edu
Advisor Ali Javey

 
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Table of Projects
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 Wei Gao, Hnin Y.Y. Nyein, Li-Chia Tai, Ziba Shahpar
Abstract Wearable sensor technologies play a significant role in realizing personalized medicine through continuously monitoring an individual’s health state. Human sweat is an excellent candidate for non-invasive monitoring as it contains physiologically rich information. Given the complexity of sweat secretion, simultaneous and multiplexed screening of target biomarkers is critical and full system integration to ensure the accuracy of measurements is a necessity. A mechanically flexible and fully-integrated perspiration analysis system is developed simultaneously and selectively measures sweat metabolites (e.g. glucose and lactate) and electrolytes (e.g. sodium, potassium, calcium and pH), as well as the skin temperature to calibrate the sensors' response. The work bridges the technological gap between signal transduction, conditioning, processing and wireless transmission in wearable biosensors by merging plastic-based sensors that interface with the skin, and silicon integrated circuits consolidated on a flexible circuit board for complex signal processing. This wearable system can be used to measure the detailed sweat profile of human subjects engaged in prolonged indoor and outdoor physical activities, and infer real-time assessment of the physiological state of the subjects. The platform enables a wide range of personalized diagnostic and physiological monitoring applications.
Contact Information weigao@berkeley.edu, hnyein@berkeley.edu, j.tai@berkeley.edu, zibas@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 active 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 IDBPN777
Project Title Nonepitaxial Growth of Single Crystalline III-V Semiconductors onto Insulating Substrates
Status Continuing
Funding Source Federal
Keywords
Researchers Kevin Chen, Sujay Desai
Abstract III-V semiconducting materials have many characteristics such as high electron mobilities and direct band. gaps that make them desirable for many electronic applications including high performance transistors and solar cells. However, these materials generally have a high cost of production which significantly limits their use in many commercial applications. We aim to explore new growth methods which can grow high quality crystalline III-V films, using InP as an example substrate, onto non-epitaxial substrates. In addition to excellent crystal quality, critical considerations include cost and scalability for commercially viable applications.
Contact Information kqchen@eecs.berkeley.edu, sujaydesai@eecs.berkeley.edu
Advisor Ali Javey

 
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Physical Sensors & Devices
Project IDBPN747
Project Title Electronic Skin: Fully Printed Electronic Sensor Networks
Status Continuing
Funding Source NSF
Keywords Flexible, printed electronics, thin film transistor
Researchers Kevin Chen
Abstract Large area networks of sensors which are flexible and can be laminated conformally on nonplanar surfaces can enable many different applications in areas such as prosthetics, display technology, and remote stimuli monitoring. For large area applications, printed electronics are favorable over traditional photolithography and shadow mask technology from a cost and throughput point of view and we demonstrate proof-of-concept for such a printed “electronic skin” system by printing a carbon nanotube based thin film transistor (TFT) active matrix backplane using a reverse roll to plate gravure printing design. This design allows for yields of up to 97% with printing conducted in an ambient environment and mobilities of up to 9 cm2/V⋅s, the highest reported for a fully printed TFT. Various materials are explored for the integration of sensors within this fully printed process scheme for multifunctional electronic skin.
Contact Information kqchen@eecs.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, Hsin-Ping Wang
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 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, Thomas Rembert
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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Wireless, RF & Smart Dust
Project IDBPN828
Project Title Zero Quiescent Power Micromechanical Receiver
Status New
Funding Source DARPA
Keywords
Researchers 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 liur@eecs.berkeley.edu, ctnguyen@eecs.berkeley.edu
Advisor Clark T.-C. Nguyen

 
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Wireless, RF & Smart Dust
Project IDBPN540
Project Title Temperature-Stable Micromechanical Resonators and Filters
Status Continuing
Funding Source Industry
Keywords µmechanical resonator, electrical stiffness, compensation, frequency drift
Researchers Alper Ozgurluk
Abstract This project aims to suppress temperature-induced frequency shift in high frequency micromechanical resonators targeted for channel-select filter and oscillator applications. A novel electrical stiffness design technique is utilized to compensate for thermal drift, in which a temperature-dependent electrical stiffness counteracts the resonator’s intrinsic dependence on temperature caused mainly by Young’s modulus temperature dependence.
Contact Information ozgurluk@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 New
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 ozgurluk@eecs.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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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 extending the effective lifetime of air-sensitive and moisture-sensitive sensors.
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 To exploit the true potential of ubiquitous connectivity at scale, wireless nodes in a sensor network need to have a long lifetime and low cost. To reduce the cost of a sensor node, complete system integration is needed, including communication, computation, sensing, and power management on a single integrated circuit with zero external components. Therefore, a Single Chip Mote sensor node is being developed that is intended to operate from harvested energy, requiring no external battery or other components. Low-power wireless communication plays a key role in extending the lifetime of a wireless sensor due to high active power consumption of the radio in comparison to the rest of the node. Traditional transceiver architectures also require off-chip components such as crystal oscillators and passives, which must be eliminated in order to enable a completely monolithic solution. The elimination of external components, combined with reduction in transceiver power consumption, will truly enable perpetual operation of wireless nodes at low-cost and hence realize the vision of ubiquitous connectivity at scale.
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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Physical Sensors & Devices
Project IDBPN826
Project Title Autonomous Flying Microrobots
Status New
Funding Source BSAC Member Fees
Keywords electrohydrodynamics, microrobotics, ionocraft, ion thrust, MAV
Researchers Daniel S. Drew, Craig Schindler, Brian Kilberg
Abstract Even as autonomous flying drones enter the mainstream, there has been no strong push for miniaturization by industry. 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 standard quadcoptors. The proposed mechanism, atmospheric ion thrusters, offer some advantages over traditional drone flight (e.g. with rotors) and also the opportunity to bring together multiple MEMS technology areas into one integrated system. A unique high- density field emission tetrode device combined with high-voltage solar cell arrays will provide thrust. Ultimately, integration with a low power control and communications platform will yield a truly autonomous flying microrobot with ion thrusters – the ionocraft. High-density self- aligned gated silicon field emitter arrays are currently being fabricated and tested. Simultaneously, we are seeking to demonstrate feedback control of a meso-scale ion thruster as a feasibility study for autonomous operation.
Contact Information ddrew73@eecs.berkeley.edu
Advisor Kristofer S. J. Pister

 
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Wireless, RF & Smart Dust
Project IDBPN735
Project Title Walking Silicon Microrobots
Status Continuing
Funding Source BSAC Member Fees
Keywords Microrobotics, electrostatics, actuators, MEMS, autonomous sensors
Researchers Daniel Contreras, Hani Gomez
Abstract The field of MEMS-based robotics has yet to produce a truly autonomous synthetic walking microrobot. This project seeks to develop a new generation of MEMS walking microrobots using simple processing techniques. These robots will be based on electrostatic linear actuators that will drive planar silicon linkages, all fabricated in the device layer of a silicon-on-insulator (SOI) wafer. By using electrostatic actuation, these legs will 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 and a high voltage solar cell array to achieve a fully autonomous walking microrobot. Current work is focused on characterizing the vertical force output and frictional losses of the planar SOI joints and linkages. We have demonstrated a 2 degree- of- freedom leg with motors in 30 square millimeters of silicon, with a vertical range of travel of 300µm and a horizontal range of travel of 1mm. Forces along the vertical axis have been measured to be over 200µN.
Contact Information dscontreras@eecs.berkeley.edu
Advisor Kristofer S. J. Pister

 
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Physical Sensors & Devices
Project IDBPN802
Project Title Electret-Enabled Energy Harvesters for Use Near Current-Carrying Conductors
Status New
Funding Source Federal
Keywords Electret, magnetic actuation, AC power lines
Researchers Zhiwei Wu
Abstract The purpose of this project is to employ long-lived electrets in energy harvesters for use on power lines.
Contact Information zway@berkeley.edu, rwhite@eecs.berkieley.edu, paulwright@berkeley.edu
Advisor Richard M. White, Paul K. Wright

 
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Physical Sensors & Devices
Project IDBPN801
Project Title Emergency Power-Line Energy Harvesters
Status New
Funding Source Federal
Keywords Energy harvester, overhead power distribution, system damage
Researchers Zhiwei Wu
Abstract The primary purpose of this project is to develop inexpensive energy harvesters for mounting on the conductors of overhead power distribution lines to energize sensors that evaluate the functioning of the line and detect physical damage to it caused by extreme weather conditions or by intentional sabotage. We also intend explore the use of these harvesters for powering co- located environmental sensors.
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 IDBPN838 New Project
Project Title Dosimetry Dust: An Implantable Dosimeter for Proton Beam Therapy Treatment of Ocular Melanomas
Status New
Funding Source BSAC Member Fees
Keywords Implantable Dosimetry, proton beam therapy, ultrasound power harvesting, ultrasound communication, piezoelectric transducer
Researchers Stefanie Garcia
Abstract Proton beam therapy is a well-established medical procedure for treating certain kinds of cancer, and is uniquely suited for treatment of head, neck, and eye tumors. In order to effectively treat a patient’s tumor, medical physicists have developed various simulations to model proton interactions with tissue and create a patient specific treatment plan that determines optimal gaze angles, the depth of penetration, and width of the spread-out-Bragg Peak necessary to encompass the target tumor. Despite the continuous improvements in medical physics treatment plan simulations, improper tissue irradiation can easily occur if there is a physical shift in the tumor and/or critical organs during the irradiation process (ex. patient movement). Currently, there are no micro-implantable feedback methods to assure proper irradiation of a tumor, and inform a physician what the in vivo dose is. We propose the use of a MOSFET silicon based radiation detector that employs ultrasonic power harvesting and backscatter communication through the use of a piezoelectric transducer.
Contact Information stefanievgarcia@berkeley.edu
Advisor Michel Maharbiz, Mekhail Anwar

 
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Wireless, RF & Smart Dust
Project IDBPN848 New Project
Project Title Highly Integrated, Compact Wearable Ultrasound System for Chronic Biosensing
Status New
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 Maharbiz, Bernhard Boser

 
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Physical Sensors & Devices
Project IDBPN731
Project Title Flexible Electrodes and Insertion Machine for Stable, Minimally-Invasive Neural Recording
Status Continuing
Funding Source DARPA
Keywords neural recording, scalable, flexible, surgical robot, minimally invasive
Researchers Timothy L. Hanson
Abstract Current approaches to interfacing with the nervous system mainly rely on stiff electrode materials, which work remarkably well, but suffer degradation from chronic immune response due to mechanical impedance mismatch and blood-brain barrier disruption. This current technology also poses limits on recording depth, spacing, and location. In this project we aim to ameliorate these issues by developing a system of very fine and flexible electrodes for recording from nervous tissue, a robotic system for manipulating and implanting these electrodes, and a means for integrating electrodes with neural processing chips. We have fabricated six versions of the electrodes, and have demonstrated their manual and automated insertion into an agarose tissue proxy, ex-vivo brain, and in-vivo rat using a micro-welded. We have also fabricated and tested in rats four revisions of the inserter robot. The most recent inserter robot design uses replaceable cartridges for the electrodes, to which electrodes are mounted; these electrodes are made on a 4um thick polyimide substrate with a parylene peel-away backing. The parylene backing holds the fine wires and keeps them from tangling until they are inserted, and provides a more robust means of handling and mounting the structures. Similarly, both the insertion needle and micro-drill can be replaced intra-operatively via cartridges. We have developed a machine for micro-brazing the insertion needle. In vivo tests of the system are ongoing, but we have shown that the electrodes record neural activity well, and are currently assessing longevity and histological response.
Contact Information tlh24@phy.ucsf.edu
Advisor Michel M. Maharbiz, Philip N. Sabes

 
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Package, Process & Microassembly
Project IDBPN823
Project Title Automated System for Assembling a High-Density Microwire Neural Recording Array
Status Completed
Funding Source State
Keywords
Researchers Travis L. Massey
Abstract Assembly at the microscale involves manipulation of one or more components relative to another in order to create a microstructure or device composed of these two or more components that would be difficult or impossible to monolithically fabricate. One specific class of problems that is well suited to microassembly rather than microfabrication is the creation of very high aspect ratio out-of-plane microstructures. As size and complexity of these out-of-plane microstructures grows, it becomes compelling if not necessary to automate the device assembly. To this end, we are developing an automated assembly system for one such device, a microwire-style microelectrode array (MEA) for textit{in-vivo}neural recording and stimulation.
Contact Information tlmassey@eecs.berkeley.edu
Advisor Michel M. Maharbiz, Kristofer S.J. Pister

 
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BioMEMS
Project IDBPN573
Project Title Carbon Fiber Microelectrode Array for Chronic Stimulation and Recording
Status Continuing
Funding Source DARPA
Keywords carbon fiber microelectrode electrode array electrophysiology chronic stimulation recording high density
Researchers Travis L. Massey
Abstract This project aims to create an array of carbon fibers for neural recording and stimulation.
Contact Information tlmassey@eecs.berkeley.edu
Advisor Michel M. Maharbiz, Kristofer S.J. Pister

 
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Wireless, RF & Smart Dust
Project IDBPN844 New Project
Project Title Wireless Sub-Millimeter Temperature Sensor for Continuous Temperature Monitoring in Tissue
Status New
Funding Source DARPA
Keywords Sensor, wireless, monitoring, biomedical, chronic, implant, temperature, thermometer, ultrasound, backscatter
Researchers B. Arda Ozilgen
Abstract Variations in tissue temperature over extended periods of time may be used to monitor tissue function, especially for several disease states and medical conditions. Current techniques employed for the assessment of tissue temperature in a clinical environment require large, expensive imaging tools and interventions that may alter patient state, cause discomfort to the patient or take extended periods of time to obtain a single measurement. Our group has previously demonstrated miniature wireless sensors employing ultrasonic backscatter enabled by the favorable properties of ultrasonic propagation in tissue when compared to electromagnetics. In this work we employ similar principles to demonstrate the development of a wireless sub-millimeter temperature sensor for continuous temperature monitoring in tissue of awake and freely behaving subjects.
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 >10^6 fold in ~1 min using only a DC power supply.
Contact Information steven_lu@berkeley.edu
Advisor Michel M. Maharbiz

 
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BioMEMS
Project IDBPN771
Project Title Silicon Carbide ECoGs for Chronic Implants in Brain-Machine Interfaces
Status Continuing
Funding Source BSAC Member Fees
Keywords
Researchers Camilo A. Diaz-Botia
Abstract Several technologies have been developed for interfacing with the brain such as microwires, electrode arrays, and electrocorticography (ECoG) arrays. While each of them has strengths and weaknesses, they all share a common disadvantage of limited device longevity due to a variety of failure modes; these include scar tissue formation and material failure, among others. A particularly pronounced problem is the failure of the insulating material at the insulator-conductor interfaces (e.g. recording sites and insulated conducting traces). Damage to these vital interfaces compromises device performance by altering the impedance of recording sites, or more deleterious, results in total device failure due to shorting between traces or between a trace and physiological fluid. To address these material issues, we have focused on the fabrication of silicon carbide (SiC) electrode arrays. As a surface coating, polycrystalline SiC has been shown to promote negligible immune glial response compared to bare silicon when implanted in the mouse brain. Additionally, due to its mechanical and chemical stability, SiC serves as stable platform and excellent diffusion barrier to molecules present in the physiological fluid. Moreover, and of particular interest to the neuroengineering community, the ability to deposit either insulating or conducting SiC films further enables SiC as a platform material for robust devices. Leveraging these unique properties, we have developed a fabrication process that integrates conducting and insulating SiC into 64-channel ECoG arrays. Recording sites 40 um in diameter are made of n- doped SiC while the insulating layers are either amorphous SiC or undoped polycrystalline SiC. To allow for low impedance interconnects, a metal stack of titanium/gold/titanium or a titanium/platinum is completely embedded in between layers of SiC. The result is an ECoG array that, to the physiological fluid, appears simply as a single SiC sheet wherein boundaries between conducting and insulating layers are seamless. The inner metal layer is well protected by SiC and therefore cannot be reached by molecules present in the physiological fluid. We believe this basic platform can be extended to a variety of electrophysiological devices, including penetrating probes of various geometries, and help mitigate the failure modes of the present technologies.
Contact Information cadiazb@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 NSF
Keywords prostate cancer, beta radiation, Solid-state detectors, Low noise, CMOS, Imaging
Researchers Stefanie V. Garcia
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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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, stochastic control, hybrid biological systems, bacterial electrophysiology
Researchers Tom J. Zajdel, Alyssa Y. Zhou
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. A primary goal of this work is to enable abiotic/biotic two-way communication via electron transfer channels engineered into cells in contact with microelectrodes. We have successfully miniaturized an electrochemical sensing platform to the centimeter scale to measure current generated by engineered bacterial cells in response to their environmental arsenic.
Contact Information zajdel@eecs.berkeley.edu, alyssa.zhou@berkeley.edu, maharbiz@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 Dongjin Seo
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 djseo@eecs.berkeley.edu
Advisor Michel M. Maharbiz

 
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Physical Sensors & Devices
Project IDBPN808
Project Title Acoustic Detection of Neural Activity
Status Continuing
Funding Source Fellowship
Keywords
Researchers Konlin Shen
Abstract There is a need for non-invasive methods of neural probing without genetic modification for both clinical and scientific use. It has been found that action potentials are accompanied by small nanometer-scale membrane deformations in firing neurons. These mechanical waves, known as “action waves”, travel down axons in concert with action potentials and could be used to determine neuronal activity. Because acoustic waves are far less lossy in the brain than electromagnetic waves, we believe it may be possible to detect action waves from neurons up to 4 millimeters away with a micromachined hydrophone. The detection of such acoustic signals could pave the way for both high resolution non- invasive recordings of neuronal firing as well as implantable probes with recording volumes much larger than conventional extracellular electrophysiological recording electrodes.
Contact Information konlin@berkeley.edu, maharbiz@eecs.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