IAB meeting Project Public Abstracts

A series of micro test structures were designed for incorporation into UCB
Microlab’s CMOS baseline process. The MEMS devices, known as
electrostatic mono-directional in-plane displacement microactuators,
enable the direct evaluation of a material’s mechanical characteristics.
Modulus of elasticity, rupture, and fatigue may all be determined for a
variety of thin film materials using these microstructures. Silicon
carbide, silicon germanium, and poly-silicon are some examples of
materials that are compatible for evaluation with devices. The
microactuators essentially consist of distinctive combdrives that actuate
against a specially designed mechanical element. Deformation and/or
failure of this element can be observed verses an applied force from the
combdrive, thus allowing test material characteristics to be determined.
Roughly 90% of the MEMS devices are fabricated from the CMOS baseline
process alone. This is followed by a few simple steps of post CMOS
processing. The final steps consist of a test-material deposition,
pattern, etch, and release, which completes fabrication of the standalone
MEMS devices.

Nanoshift, LLC is a privately held research and development company
specializing in Bio-MEMS, MEMS, Micro- and Nanotechnologies. It utilizes a
network of talented individuals and flexible research facilities to provide
custom services in process development, rapid prototyping, fabrication and
consultation. Nanoshift actively engages the projects of emerging
technologies. Typical projects arrive from both academics and industry;
Nanoshift is positioned as the road map for concept to product
advancement. Projects can be contracted over any time scale, however, the
majority of contracts are revolving ones that require best efforts to meet
or exceed innovative milestones. 
Nanoshift is collaborating with BSAC to make more powerful resources
available for its members. Nanoshift offers valuable services and
technical expertise to both academic and industrial members while
increasing BSAC's visibility, funding and resources.

Optical packaging differs from traditional packaging in several ways, and
many of these differences emerge from the need to protect the electrical,
mechanical, and optical components of a system while preserving its
exposure to the environment. Thus, the materials and packaging processes
involved in such a system must be chosen with these goals in mind. This
research project seeks to ascertain reliable and feasible hermetic
packaging methods to ensure mechanical durability as well as insulation
from electrical leakage for an optical feed-through operating in highly
variable temperature environments. Several sealant materials and bonding
processes appropriate for hermetic sealing are discussed in terms of
induced stress, hermetic lifetime, and electrical characteristics. From
this preliminary evaluation, hermetic bonding experiments and reliability
tests are conducted. Finally, this study offers basic guidelines for the
materials and processing techniques needed for this system with several
design variations considered.

Silicon Carbide (SiC) Sensors are appealing for harsh environment MEMS
applications, specifically because of their ability to withstand high
temperatures. The long range goal of this project is to develop a fast and
efficient process to bond SiC strain sensors to various metal components to
obtain high-precision measurements. Inductive heating shows much promise
for die level bonding because it is capable of rapidly heating die-sized
areas to form localized bonds.

Non-magnetic heaters are desirable for systems sensitive magnetic fields,
such as micromachined gyroscopes using spin-polarized nuclei.  The
short-term objective of this project is to design and fabricate MEMS
resistive heaters that will generate minimum magnetic field while under
resistive heating to provide the heating source for the micromachined
gyroscope using spin-polarized nuclei.  The long-term goal of the project
is the integration of the non-magnetic heater with other components to
accomplish micromachined gyroscope using spin-polarized nuclei within the
magnetic shielding packaging.

Tools for linking the environment (application/tester/customer system) with
the micro world of a MEMS device are extremely limited. It has proven
difficult to accurately predict package, tester, and circuit board
interactions and results. Thus, this research aims (1) to explore the
physics of micro/macro interfacial contacts/stresses in the back-end
packaging process to the overall MEMS RF device performances, and (2) to
develop models for stresses in packages with MEMS devices (including RF
MEMS such as QFN, LGA, cavity packages, etc.) both in process and final
product stages. The long-term objectives for this project are to improve
MEMS device performance over temperature as a result of optimization from
predictive modeling, and to understand and engineer the physics of
micro/macro bonding interface in order to improve the system performances
in terms of stability, reliability, and offset.

Glass frit bonding is a largely popular method of encapsulating MEMS
devices in the industry today.  It's popularity is due to relatively low
processing temperature, tunability of thermal coefficient of expansion,
and hermetic sealing.  However, glass frit bonding requires a large amount
of space, sometimes as much as several times the size of the MEMS device
itself.  This attribute is largely responsible for limiting further
scalability and miniaturization of individual dies. This research project
aims (1) to take a deeper look into the shortcomings of the existing glass
frit bonding technique, (2) to identify novel packaging materials and/or
techniques for bonding, and (3) to gain a deeper understanding of the
stresses induced during and after the packaging process. The long-term
objective of this project is to understand and engineer the physics of
micro/macro bonding interface to improve the system performances in terms
of stability, reliability, offset.

This project aims to create packaging featuring a micro-fabricated magnetic
shield for a micromachined gyroscope that utilizes spin-polarized nuclei. 
The final package is to fit in a volume of one cubic centimeter while
allowing signal transmission lines to communicate with outside world.  The
goal for shield attenuation (the shielding factor) is a value greather than
10^5.  Small magnetic shields have been fabricated and tested, and
numerical simulations have been conducted as well.  Current work focuses
on new methods of fabricating shielding devices and the exploration of
additional shielding materials.

With the development of transdermal drug delivery methods there is a
growing potential for creating safer and more efficient means of vaccine
delivery and improving access for children in remote areas of developing
countries. Problems with conventional needle delivery in areas with
limited supplies include the risk of blood borne pathogen transmission
through accidental needle sticks, wastage and contamination during the
reconstitution process, storage and cold chain maintenance. Microsyringe
systems consisting of an array of pointed, out-of-plane microneedles have
been proposed for painlessly delivering a single dose of a lyophilized
drug across the stratum corneum. Initial studies of these devices have
occurred in both animals and humans demonstrating proof of concept. Lower
cost devices are being developed but have yet to be characterized in terms
of successful delivery of vaccines.

The goal of this project is to develop a polymer microfluidic system to
test system level performance.  The chip will be plastic injection molded
with integrated fluidic interconnects.  Polymer film with patterned metal
traces will be used to enclose the channel.  The traces will allow simple
control elements such as heaters and electrodes to be integrated into the
chip.  Previous work at UC Berkeley has developed a thermal sensitive
hydrogel valve that can be lithographically patterned.  This valve will be
incorporated into the chip and actuated via on-chip heaters.  A test assay
will be performed in this device to measure system level parameters such
as frequency, accuracy, and repeatability.

In this project, near-field electrospinning (NFES) is applied for
site-specific, chip-to-chip micro/nano fluidic interconnectors. This
fabrication/packaging technology enables off-chip fluidic transportations
through fluidic channels of 50nm~5μm in diameter. Near-field
electrospinning has the position controllability better than 10μm in
contrast to the random deposition of conventional electrospinning.

A scanning-probe magnetic microscope based on a high resolution magnetic
tunnel junction (MTJ) sensor is under construction. The completed
microscope will be used to characterize the magnetic properties of
ferromagnetic metal samples. The sample under test is scanned across the
MTJ sensor using a computer-controlled xy stage and magnetic field
measurements are recorded as a measure of the magnetic properties of the
sample.   The preliminary automation software has been developed, and the
repeatability and accuracy of the sample position control have been
experimentally characterized.  Currently, we are investigating techniques
to integrate the MTJ sensor with MEMS actuators for position control and
magnetic field modulation.  We have developed a set of actuator designs;
the actuator designs were modeled using finite element and fabricated with
surface micromachining techniques.

The goal of this project is to develop technologies for hierarchical
assembly of nano structures (silicon nanowires (SNWs) and carbon nanotubes
(CNTs)) with built-in CMOS interface circuits by utilizing localized and
selective IC-compatible synthesis, for a fully integrated nano-sensing
system. Ultimately, both the nano-sensor element and the signal processing
circuits should be fabricated on the same device substrate. The SNWs/CNTs
will be synthesized afterwards locally and selectively using MEMS
resistive heaters. In order to develop the integration process, we plan to
use the 0.35 microns CMOS standard testing process that has been running
continuously in our microfabrication lab at UC-Berkeley as the foundation
for microelectronics. The SNW/CNT with on-chip ICs could have many
potential applications, such as physical (including temperature, pressure,
and gas detectors), biological and chemical sensors, as well as nano
electronics.  The long-term objective of this project is to investigate
MEMS/NEMS interfacial contact physics and impact to electrical/mechanical
properties of system.

The goal of this project is to develop a microelectronics-compatible
synthesis method for Carbon Nanotubes for integration with MEMS devices.

The primary objective of this work is to develop a platform technology for
the rapid synthesis nanostructured materials using an induction heating
system.  The technology is clean, energy efficient, and inexpensive, and
may be used to rapidly synthesize nanomaterials in a room-temperature,
cold-wall reactor environment in as little as 30 seconds.  The technology
is versatile, enabling bulk synthesis on various different conductive
substrates, localized synthesis and integration on ring-shaped MEMS
structures, and may potentially be used for plasma-based synthesis.  The
technology is also scalable allowing for chip-scale and theoretically
wafer-scale synthesis.  Such a synthesis technique, with a unique heating
profile and rapid turnaround time, may be used to quickly prototype novel
vapor-liquid-solid-grown nanomateraials, enable wafer-scale, rapid
synthesis and integration of nanomaterials for sensor applications, and
open up a novel class of nanomaterial synthesis including the discovery
new nanostructures.

Electrospinning, based on a high electrostatic field driving mechanism, can
fabricate long and continuous nanofibers with diameters less than 100nm.
This project aims to investigate the feasibility of incorporating
electrospinning as a new micro/nano manufacturing tool for micro/nano
device fabrication. The project starts with the exploring the
electrospinning mechanism and determining the feasibility of near-field
electrospinning (NFES) for low driving voltages, tracking control, and
clog prevention. The next step will be the integration of NFES with
micro/nano fabrication to make functional devices. The concept and initial
demonstrations of NFES suggest that electrospinning can be extended to new
applications previously unachievable by conventional means.  Specifically,
we are interested in the directions of integrated nanofiber sensors,
fluidic channels and interconnects, and biological applications.

The project is to develop a CMOS compatible Carbon Nanotube (CNT) based gas
sensor for analyzing the gas mixture. CNT has good qualities for micro/nano
scale gas sensing because of its sensitivity to noble gases and various
oxidizing gas species with a large range of working temperature in the
harsh environment. The possible gas absorption mechanisms include
physiorptions and chemisorptions and further investigations are needed for
fundamental understandings. Moreover, CNT’s responsibility to oxygen has
been proposed as the effect of doping the nanotube at the defects and the
Schottky barrier effect at the CNT-metal contact. Utilizing the techniques
of in situ CNTs synthesizing, we are able to build sensing elements in the
form of single nanotube or compact nanotube layers. We will investigate
the performances of electrical gas sensing and resonator based sensing.
Sensitivity < 1ppm and short response time (i.e. < 1 msec) and
reversibility are the desired performances of the device.

Semiconductor nanowires have recently stimulated great interest due to
their attractive and potentially very useful properties, originating from
features such as carrier confinement, high surface to volume ratio, and
morphology/crystal structure unique to their nanoscale dimension and
bottom-up growth process.  These properties lead to many possible
applications such as room temperature ballistic conductors for
high-frequency/high-powered integrated circuits, UV/visible/IR nanolasers
and waveguides, as well as sensors for chemical and biological agents. 
The systematic assembly and integration of nanowires into electrical and
electro-optical devices, however, remain a formidable challenge.  The goal
of this project is to address this problem and develop a novel 2D
individually-addressable nanowire array to serve as the platform for
future device applications.

This project first aims to develop a process flow to integrate silicon
nanowires directly on top of a CMOS substrate. Then, by carefully
designing the underlying circuitry and functionalizing the nanowire
transducers, we hope to demonstrate a fully functional integrated sensing
platform for various molecular agents. Combined with the efforts of others
in our research group, the overall goal is to create a low-cost and
easy-to-use CMOS-based system for detecting agents at the molecular level
in the point-of-care (POC) setting.

We constructed a pair of parallel conducting metal (Ag) plates separated by
patterned molecular monolayers at the corners of the plates. A special
metal deposition process was developed to ensure atomic scale flatness in
the conducting plates. The separation between the plates can be
controllably varied between several angstroms and tens of nanometers by
varying the length of the molecules and/or employing conventional
substrate processing techniques. The structure is an efficient sensor for
detecting single molecules via surface enhanced Raman spectroscopy (SERS).
The unique configuration of the plates also allows for investigation of
Casimir force between two parallel plates and helps in elucidating some of
the unexplained observations in molecular electronic junctions.

A photoresist-polysilicon cantilever bimorph prototype was designed,
fabricated, and tested. Two types of this device were formed with
different readouts; one required an optical readout while the other used a
capacitive readout. Devices were characterized using optical and thermal
methods. Time response and spectral sensitivity were measured.  Future
goals include detailed characterization of the current prototype,
analytical model correlation, low-pressure testing, and geometric
optimization.  In addition, prototypes using Chitin and other polymers
will be fabricated for comparison.

The focus of this project is on developing parametric MEMS resonators for
application to gyroscopes, magnetometers, and RF MEMS filters. Optical
parametric oscillators and microwave parametric amplifiers are widely
utilized but their current MEMS counterparts are largely an academic
curiosity. Parametric MEMS resonators have a number of  advantages over
the current state-of-the-art in MEMS resonator technology. First, they
allow direct mechanical amplification of the sensor input, reducing the
requirement for electronic amplification and allowing a corresponding
reduction in power consumption. Second, in devices that are
electronic-noise limited (rather than Brownian-noise limited), parametric
amplification allows an increase in the signal-to-noise ratio. Third, in
gyroscopes, the fact that the parametric amplification is phase-locked to
an input pump frequency allows selective amplification of the Coriolis
signal without amplifying the quadrature signal.

A serious worldwide infrastructure problem is the sudden, often dramatic
failure of underground high-voltage AC power distribution cables.  This
research is aimed at finding economical ways of sensing the health of,
preferably, in-service cables, operating at tens of kilovolts, to permit
their selective replacement.

Current trends in miniaturization indicate the reduction in size of all
electronic devices, and satellites are no exception.  Drawing from
progress in wireless sensor network technology, microsystems can
potentially be used in such communication networks.  This project
considers the deployment of small-scale satellites for these orbital
systems.  The limits on miniaturizing a ground-to-orbit system are
considered, and in particular, conditions on and designs for the orbital
insertion of sub-kilogram payloads are examined.  A specific rocket
architecture with a feedback controller for trajectory guidance is
proposed to get a 10 gram sensor mote into low earth orbit (LEO).  The
controller uses a three axis angular rate sensor for trajectory
measurements, and a prototype system has been built and tested.

Silicon Carbide (SiC) is an appealing material for harsh environment MEMS
application. The goal of this project is to develop, optimize and scale-up
polycrystalline SiC thin film as a structural layer for harsh environment
TAPS (Temperature, Acceleration, Pressure and Strain) sensors.
We will pursue two new precursors, namely methylsilane and
methyltrichlorosilane for chemical vapor deposition of SiC.  The research
will aim to develop the process parameters to obtain high quality poly-SiC
films with reasonable growth rates, high uniformity, controlled residual
stress, controlled strain gradient, and controlled resistivity.

The goal of this work is to deliver a sensor module with MEMS-based silicon
carbide TAPS sensors integrated with SiC interface circuits for extreme
harsh environment applications.

The goal of this research program is to deliver a sensor module with
MEMS-based silicon carbide TAPS (Temperature, Acceleration, Pressure and
Strain) sensors integrated with SiC interface circuits for extreme harsh
environment applications.

The main objective of the project is to design and fabricate capacitive
sensors capable of performing under harsh environments.

The main focus of the project is to develop a strain gauge which measures
strain at micron scale to improve the operational characteristics of its
substrates in applications such as automotive and aerospace. Contrary to
traditional and commercial strain gauges, temperature and aging have a
relatively small influence on the sensitivity and precision of this type
of sensor. 

Three major goals have been set for the course of research. The most prior
goal is to resolve the cross-axis strain sensitivity using a mechanically
compliant design. The next goals are to maintain high sensitivity,
resolution and manufacturability for the sensor. This strain sensor is
capable of measuring micro-strain (1e-6) with a gauge length less than 1
mm and also operates by in-situ mounting on the substrates. This static
gauge maintains enough sensitivity and linearity over a wide range of
temperatures and harsh environments. In particular, a differential
capacitive method is used to transduce strain into an electrical signal
via capacitive sensing.

A high-g harsh environment resistant accelerometer is also part of the
promise of this project. This accelerometer will be capable of high-g
shock measurements.

The MEMS silicon strain gage can be oriented and placed on round tubing
such that it can be utilized as a torque measurement device.  To this
extent, a shear strain application system has been designed and is
currently being constructed.  This device utilizes a common automotive
halfshaft, a component which would see fairly high torques during its
lifetime and could benefit from torque monitoring systems.  Validation of
the strain application system has been completed, and strain gauge device
testing is commencing.  The testing will focus on characterizing strain
transfer and strain gauge linearity.

This overall project aims to apply mechanicaldisplacement amplification to
improve the performance of various micromechanical signal processors, for
analog as well as digital applications.

The overall goal of this project is to demonstrate a switched-mode power
converter (e.g., a charge pump) using micromechanical switching elements
that allow substantially higher voltages and potentially higher conversion
efficiencies than transistor-switch based counterparts.

This overall project aims to demonstrate methods for amplifying signals
with higher efficiency compared to transistor circuitry using strictly
mechanical means for ultra-low-power signal processing applications.

Conventional pipeline Analog-to-Digital converters require high open-loop
gain amplifiers operated in feedback configurations to achieve precise
inter-stage gain.  This approach is costly because these OTAs drive not
only the load capacitors, but also the sampling and feedback capacitors. 
As a result, the power consumption of the amplifier can be a feedback
factor worse than its open loop counterpart (i.e., 2 to 3X).  Thus, the
goal of this project is to significantly reduce the power consumption of
pipeline ADCs by eliminating this “feedback penalty”.

The goal of this project is to create useful, efficient design synthesis
tools for MEMS devices. Design synthesis helps engineers develop rapid,
optimal configurations for a given set of performance and constraint
guidelines. The current MEMS design synthesis tool is based on a
case-based design library and uses variant optimization techniques for
adapting old designs to new design problems. The design synthesis tool
recommends the initial designs to the designer based on the given design
specifications and further optimizes the design parameters to satisfy the
design performance requirements and constraints. Through the use of a
multi-objective genetic algorithm (MOGA) and local optimization
techniques, the MEMS design synthesis tool can provide multiple good
design concepts to a MEMS designer for further engineering analysis.  The
best designs generated from the design synthesis process will be
fabricated and tested, and the successful designs will be stored in the
design case library for future use.

The goal of this project is to make low-cost, low power, and reconfigurable
electromagnetic-wave beam-formers for potential W-band applications such as
car collision avoidance radar, wireless local network (LAN), and radio
links. The beam-forming is realized by phased antenna array. This research
project responds to the need for complete system-level integration of RF or
millimeter-wave (MMW) systems. We will develop technologies for 3-D
structures by industrial plastic molding and electroplating processes with
integrated active/passive components and reconfigurable beam-formers.  This
molding-based architecture enables low-cost manufacturing and integration
of 3-D micro electromagnetic-wave components, such as antennas, coaxial
transmission lines, waveguides, phase-shifters and tuners, with capability
to integrate monolithic IC components to achieve low-cost micro
beam-formers.

An enabling technology for large scale sensor networks is the ability to
determine a sensor node’s location after deployment. Some applications,
such as inventory management, use sensors that move regularly, and this
spatial information is crucial to the network's operation. A device to
wirelessly measure the distance between two network nodes using an RF
transceiver will be developed. The distance measurement is performed by
calculating a cross correlation between a received and an expected signal.
Methods for reducing the effects of noise, clock offset and multipath
propagation have been studied, and mitigation techniques have been
implemented. We have demonstrated round trip time of flight (TOF) ranging
using an FPGA, 2.4 GHz radio, and a custom PCB. Meter level accuracy has
been demonstrated both indoors and outdoors. The end goal is to provide
low power, accurate, self-contained, ad hoc localization to mobile sensor
nodes.

Target localization, the ability to determine the location of a target, is
becoming increasingly attractive for purposes of security and automation. 
Vibrational localization is the method of sensing and calculating the
target’s location using vibrations transmitted through the ground.  This
method of localization does not require a line of sight to the target, is
not limited by dilution of precision, and can detect any moving object or
person.  Vibrational localization was formerly restricted by the noise
performance and sensitivity limitations of accelerometers and other
circuit components, but these restrictions are becoming less significant
with improving technology.  The goal of this project is to be able to
track a person’s footsteps in a room or hallway to a precision of twenty
centimeters.

Our long term goal is to develop and implement novel sensors and sensor
applications for automobiles. Research will take a hands-on approach of
wiring an existing race car, designed and fabricated by the UC Berkeley
Formula SAE student race car team, with commercially available
off-the-shelf sensors used in the racing industry. This includes wheel
speed sensors, shock position sensors, steering angle sensor, brake
pressure sensors, and accelerometer. Sensors under development include
strain gauges, used to measure chassis flex and wheel loading at the
suspension pushrods, as well as strain gauges to wirelessly measure output
torque at the driveshaft.

The overarching goal of this multi-unit UCB project is to identify
technology to enable domestic electricity users to make more effective use
of electric power.  Elements include inexpensive wireless metering of
electric energy use, and thermal/humidity monitoring and control inside
houses based on weather information ? both present conditions and
short-range predictions -- and electric power prices.  The term ?demand
response? (DR) refers to the ability of electricity users to respond
automatically to time- and location-dependent electric energy price and
supply contingency information in order to tailor their electric energy
usage.

This project involves optimization of a portable MEMS-based instrument that
quantifies and differentiates fine airborne particulate matter
concentrations of such substances as diesel engine exhaust, environmental
tobacco smoke, and wood smoke.  The goal of the project is integration
with and interfacing of the instrument to a cellular telephone for mobile
monitoring.

This project aims to develop levitated ultra-high-Q micromechanical
resonators based upon the principle of diamagnetism and/or electrostatics.
These magnetic and electrostatic actuation schemes obviate the need for
supports, thereby eliminating design-imposed anchor-to-substrate energy
loss mechanisms and perhaps revealing the intrinsic Q of resonator
materials. In addition, on-chip signal-conditioning circuitry will be
developed and integrated together with resonators, providing precise
control over the lateral position of the resonators.

This project aims to demonstrate an RF filter with unprecedentedly small
percent bandwidth and low loss, while still capable of handling powers
suitable for transmit in wireless communications.

This project aims to realize a UHF oscillator with long- and short-term
stability for communication applications. In the process, this work will
likely need to investigate and model scaling induced mechanical noise
sources such as derived from adsorption/desorption, thermal fluctuation
and Brownian motion, then determine the degree to which they are
correlated/uncorrelated. A modeled understanding of intrinsic
scaling-induced noise sources would reveal strategies for nulling them via
engineered surfaces, materials, and environments, or via circuit
techniques, such as arraying all of which will be explored, pursuant to
attaining on-chip oscillators and filters with unprecedented stability.

Recent advancement in wireless communication requires substantial
improvement in the performance of physical devices needed to implement
ubiquitous, multi band, multi standard and reconfigurable radio frequency
(RF) systems. Aluminum nitride contour-mode resonators have been proven as
one of the most promising technologies for the implementation of
fully-integrated single-chip transceivers, but remarkable efforts are
still needed to be undertaken in order to improve the performance of RF
MEMS filters, local oscillators and intermediate frequency (IF) filter
stages. Investigations are required to understand and control the
fundamental mechanisms that limit the resonator quality factor (Q), its
electromechanical coupling coefficient and its stability behavior with
respect to temperature fluctuations and ambient interactions. Higher Q
devices will enable record low phase noise frequency reference oscillators
for handsets, GPS and radar systems. Larger electromechanical coupling
coefficients translate into low losses and large bandwidth filters with a
reduction of the device count per function.

The aim of this project is to investigate and optimize the ambient factors
and fundamental material properties that impact the performance of AlN
contour-mode resonators. Process fabrication optimization, measurement and
simulation-based modeling for different temperatures and designs, and
material analysis techniques (SEM, TEM, AFM, X-ray diffraction) have been
extensively used to characterize and tailor the materials and device
properties in order to obtain high-performance resonators.

The Q-factor of a MEMS resonator is the result of a number of mechanisms:
many of the damping sources are related with the evironment where the
device is working such as air damping or viscous damping but many others
are an intrinsic property of the vibrating structure. Among those the most
common source of energy loss are the anchor losses, the excitation of
spurious mode and the Thermo Elastic Damping (TED). The long-term
objective of this project is to characterize the energy dissipation due to
thermoelasticity in piezoelectric materials. In particular due to the
increasing interest showed for its applications in RF-MEMS resonators,
this work will be focused on Aluminum Nitride.

The goal of this project is to use piezoelectric Aluminum Nitride (AlN)
MEMS contour mode resonators to develop RF bandpass filters which can
achieve multi-frequency per chip, CMOS compatibility and high quality
factor Q. The highly-integrated bandpass filter arrays with low power
dissipation and small form factor, will be promising technology to
accomplish next-generation wireless communication systems.

The long-term objective of this project is to realize self-temperature
compensating resonators through choice of electrode, sacrificial, and
substrate materials. In this work, a post-CMOS compatible aluminum
nitride(AlN) RF resonator is being designed. This contour mode resonator
has the advantages of permitting multi-frequency on a single chip with low
motional resistance. However, Frequency fluctuation induced by temperature
variations is the primary concern to the ultimate performance of this
devices, which currently limit it's performance in terms of frequency
stability and phase noise. Careful control of the interfaces between
electrode, resonator, and potentially other materials, should allow the
implementation of very efficient and passive schemes for temperature
compensation. The TCF of AlN of about -26 ppm/C can be compensated
by adding an additional SiO2 layer with positive TCF. As a result, ultra
stable and temperature insensitive RF resonator/filter will be possible.

The long-range goal of this project is to develop aluminum nitride (AlN)
Lamb wave resonators with small frequency-temperature shifts, high quality
factors, multi-frequencies, and CMOS compatibility on one chip.

This overall project aims to explore the ultimate performance (e.g., phase
noise in oscillators, insertion loss in filters) attainable by
micromechanical circuits as dictated by physical limitations.

Vibrating mechanical tank components, such as crystal and SAW resonators,
are widely used for frequency selection in communication  systems because
of their high Q and exceptional stability. However, being off-chip
components, these devices pose an important bottleneck against the
ultimate miniaturization and performance of wireless transceivers.

This project aims to explore the use of capacitively transduced
micromechanical circuits to realize micromechanical mixer-filters with
reconfigurable attributes. With their substantial size, cost and 
performance advantages, these devices can be used to realize a bank of
tunable/switchable micromechanical filters for multi-band RF channel
selection. By replacing all off-chip components with micromachined passive
elements, micromechanical mixer-filters offer an alternative set 
of strategies for transceiver miniaturization and improvement.

In the long term, this overall project aims to demonstrate an RF
channelizer utilizing micromechanical elements in its signal path,
exclusively, that presents one of the keys to eventually realizing a
cognitive radio.

The performance of traditional wireless receivers is limited in a large
part by the lack of a narrow bandwidth, low loss, and 
reconfigurable filter at the RF bandwidth, which leads to designers
needing to use circuit techniques to ensure adequate linearity 
and allow channel selection. This project aims to make use of recent
developments in high quality micromechanical resonators to 
enable new circuit designs featuring ultra-low power consumption and an
extremely small size. The receiver will be based around 
an array of filters to perform sub-carrier separation and allow an OFDM
signal to be received in the analog domain using extremely 
low power, simple receivers, enabling robust wireless reception.

The goal of this research is the development of RF modules for wireless
applications equipped with acoustic MEMS based filters and oscillators.
Using CMOS compatible post-processes the acoustic components are to be
fabricated directly on circuitry. In order to justify the increased
complexity of such a module besides the advantage of size and cost, this
will require a performance comparable to existing modules. Therefore the
greatest challenges concerning the acoustic MEMS filters are lowering the
insertion loss and increasing the bandwidth. The most important issue for
oscillators addressed in this project is the temperature compensation in
order to improve distortion of the phase noise introduced due to a PLL
based compensation.

Fast growing applications of terahertz frequency in different areas such as
material spectroscopy, medical imaging, radar systems, and security makes
highly efficient, compact terahertz electronics highly on demand. However,
the electromagnetic spectrum range at the corresponding frequencies
(between 0.1 and 10 THz) has not been completely explored, due to the
limitations of traditional microwave technology at long wavelengths and
optical/laser sources at shorter wavelengths.

The goal of this research is to design, fabricate, and test a wide band
oxygen sensor that operates in the combustion zone of a lean burn internal
combustion engine.  The sensor’s anticipated use is to provide a signal
that provides diagnostic information about each cylinder. Eventually this
signal may be used for real time control of injector timing resulting in
reduced fuel consumption and emissions.

The long-range goal of the project is to use silicon carbide (SiC) MEMS
sensors for in-cylinder measurements. Harsh environment compatible SiC
sensors will be used to deliver real time combustion data to a control
system, regulating engine-firing timing. A control system can then be used
to produce complete fuel combustion in flexible fuel engines.