Electrical Engineering
      and Computer Sciences

Electrical Engineering and Computer Sciences

COLLEGE OF ENGINEERING

UC Berkeley

   

2005 Research Summary

Chapter 5: MEMS & Nanotechnology

3D Millimeter-Wave Beam Formers

Firas Sammoura
(Professor Liwei Lin1)
BSAC


The goal of this project is to make low-cost, fluidic-based, and reconfigurable electromagnetic-wave beam formers for 20~95 GHz applications. This research project responds to the need for complete system-level integration of RF or millimeter-wave (MMW) systems upon a single substrate using three-dimensional printed circuit board (PCB) technology. We will develop technologies for 3D structures by industrial plastic molding and electroplating processes with integrated active/passive components and fluidic control for reconfigurable beam formers. This molding-based architecture enables low-cost manufacturing and integration of 3D micro electromagneticwave components, such as antennas, coaxial transmission lines, waveguides, phase-shifters, and tuners, with capability to integrate monolithic IC components to achieve low-cost and reconfigurable micro beam formers.

1Mechanical Engineering

Email contact: firas@me


3D Refractive Microlenses and Lenslets

Hyuck Choo
(Professor Richard S. Muller)
BSAC


The goal of this project is to fabricate 3D refractive microlenses and lenslets by surface micromachining and to investigate their use in micro-optical systems.

Email contact: hchoo@eecs


AlN Resonators: High-Q Flux Gate for CSAC

Gianluca Piazza
(Professor Albert Pisano)
BSAC


For this research project, ultra high frequency (UHF) piezoelectric resonators are fabricated from Aluminum Nitride. These actuators will be used in an Integrated, Nano Mechanically-Regulated Atomic Clock. This new atomic clock will utilize MEMS technology to make possible reductions in size, mass, and power consumption of chip-scale atomic clocks (CSAC). The primary reduction in power comes from a resonance cell employing Rb87 as the transition frequency reference. In the resonance cell, an array of shielding resonators modulate a constant magnetic field (created by a simple magnet) to provide magnetic flux reversals at 6.835 GHz using a mechanical resonance of 3.4175 GHz. Thin-film aluminum nitride (AlN) piezoelectric elements provide for the UHF actuation mechanism of these nano-mechanical resonators. UHF ring-shaped resonators have been demonstrated at frequencies as high as 656 MHz with quality factors ranging from 1,400 to 3,000 in air. The same resonators show controllable motional resistance varying from 80 to 300 U. 2 GHz FBAR-type resonators with Q of 1,000 were also fabricated using the same process.

Email contact: piazza@eecs


Background Calibration Techniques for Digitally Assisted ADC

Anshi Liang
(Professor Bernhard Boser)
BSAC


The goal of this resarch is to develop new background calibration techniques for low power digitally assisted analog-to-digital converters (ADCs). The goal is achieve significant savings in convergence time. A proof-of-concept FPGA realization calibration module will be built for a 12-bit, 75 MS/s demonstration prototype previously developed by Boris Murmann.

Email contact: lasnake@eecs


Behavior of Water and Ice in Nanocavities

J. Tanner Nevill
(Professors Dorian Liepmann1 and Luke Lee2)
BSAC


Nanogap sensors have been developed to study various biochemical reactions such as DNA hybridization, protein conformation, and polymer formation. Recently, the nanogap sensors have been used to study the dielectric properties of water and ice. It is well known that water plays a vital role in many processes on the molecular level. Without water, there would be no cell membranes, no ion transport, no protein ligand interaction, and the list can go on ad nauseum. Although we recognize how important water is to these functions, the precise role of water is still not completely understood. This project is focused on the dielectric properties of water in nanocavities. These properties can quantify how tightly individual water molecules are bound to neighboring molecules, which can provide information on the involvement of water in molecular life. Most importantly, the size scale of these nanogap sensors is similar to the size scales found in and around cells, so nanogap sensors provide excellent platforms for studying these interactions.

1BioEngineering
2BioEngineering

Email contact: nevill@berkeley.edu


Bi-Directional Electrothermal Electromagnetic Actuators and Relays

Andrew Cao
(Professor Liwei Lin1)
BSAC


Micro relays powered by bi-directional electrothermal electromagnetic actuator have been designed, built, and tested. Relays built using these actuators can have a single pole double throw (SPDT) configuration. Bi-directional actuators can be used to make bi-stable relays, which only require power consumption during the switching operations. The relays built can switch both high current and high voltages. The off state resistance is over 100 Megaohm with a breakdown voltage exceeding 200 V. The on state resistance is around 0.3 ohms and can carry several amps before failure.

The performance of these relays is enhanced using liquid metal wetted contacts. The liquid metal can increase the actual contact area of the relay, hence reducing contact resistance and the heat generated at the contacts. The liquid contact surface reduces the amount of force needed for low contact resistance, potentially increasing the mechanical lifetime of the relay and decreasing the actuator size and power consumption. The liquid metal coating could also quench the heat caused by arcing and prolong the lifetime of the contact surfaces. Testing of metal wetted gold-to-gold contacts are still in progress.

1Mechanical Engineering

Email contact: acao@eecs


Bio-Inspired Optical Imaging and Sensing System

Ki-Hun Jeong and Jaeyoun Kim
(Professor Luke Lee1)
BSAC


In this project, we will design, fabricate, and characterize compact, integrated optical image sensors with field-of-view (FOV) angles ranging from 0 to >120. In order to accomplish compactness, manufacturability, and wide FOV simultaneously, we will adopt bio-mimetic approaches in which miniature biological imaging structures exhibiting the required features are replicated based on our technical expertise in polymer micro-machining and polymer micro-optics techniques. For further miniaturization of the imaging systems, we will develop fabrication techniques for self-writing of a self-aligned microlens and waveguide array in photopolymer

1Bioengineering

Email contact: lplee@socrates


Biomimetic Nanofabrication of Silica Structures Based on Diatoms

William Joseph Holtz
(Professors J. D. Keasling1 and Roger T. Howe)
BSAC


Diatoms are a type of brown algae that create hydrated silicon-dioxide structures with feature sizes down to 5 nm at ambient temperature and pressure. The goal of this project is to replicate these processes in vitro and then manipulate the process parameters to create engineered structures.

1Chemical Engineering

Email contact: holtz@eecs


CMOS Imaging Receiver for Free-Space Optical Communication

Chinwuba David Ezekwe
(Professor Kristofer Pister)
BSAC


A 256 element CMOS imaging receiver has been designed to receive low-power, free-space optical transmissions between unmanned aircraft, or other small, low power platforms, at a distance of several kilometers.

Email contact: chinwuba@eecs


Case-based Reasoning for MEMS Design

Corie Cobb
(Professor Alice Agogino1)
BSAC


The goal of this project is to apply case-based reasoning tools to MEMS design as part of a larger MEMS synthesis architecture. Having the ability to draw upon past design knowledge is advantageous to the MEMS designer, allowing reuse and modification of previous successful designs to help deal with the complexities of a current design problem. Case-based reasoning will utilize past successful MEMS designs and sub-assemblies as building blocks stored in an indexed library. Reasoning tools will then find cases in the library with solved problems similar to the current design problem and propose an approximate solution. The case library will include useful MEMS genetic algorithm (GA) building blocks and serve as a design tool for the MEMS community. Current work is focused on case representation using the SUGAR simulation tool and the formation of an indexed database.

1Mechanical Engineering

Email contact: ccobb@me


Centura Deep Silicon and Oxide Etch Characterization

Matthew Wasilik and Ning Chen
BSAC


The Centura platform cluster-chamber system was acquired from Applied Materials and installed in the UCB Microlab in the spring of 2003. The system consists of dual loadlocks, a six inch multi-wafer, high throughput processing capacity, and two high performance etching chambers. One of the etch chambers is the DPS DT (Decoupled Plasma Source Deep Trench) deep silicon etcher. This chamber may serve as a DRIE (Deep Reactive Ion Etch) system with added capabilities. The accompanying chamber configured to the system is the MxP oxide etcher. Likewise the MxP serves as a high performance six-inch wafer oxide etch tool. After installation of the system into The UCB Microlab, Applied performed a "Tier 1" hardware qualification. This was followed by the attempt of a "Tier 2" process qualification. The MxP chamber met all of the required process specifications listed in the Tier 2 qualification. However, after several months of poor results under the guidance of Applied process staff, BSAC engineering took ownership of the Tier 2 process characterization for the DPS deep silicon process. Two designs of experiments were performed and the DPS chamber was thoroughly characterized. From this, a baseline deep Si etch process was successfully developed. The results of the characterization are to be presented.

Email contact: mwasilik@eecs


Characterization of MEMS Deformable Mirrors for Adaptive Optics

Hyunkyu Park
(Professor David Horsley1)
BSAC


This project is focused on characterizing and modeling MEMS deformable mirrors for adaptive optics. We are interested in improving both the design and control of these mirrors as well as in developing new characterization and wavefront sensing methods. Although this project is presently targeted towards the vision science applications of adaptive optics, we are also interested in other applications requiring high-speed correction.

1UC Davis

Email contact: hkpark@ucdavis.edu


Clinical Testing of MEMS-Syringes

Raja Sivamani and Boris Stoeber
(Professors Dorian Liepmann1 and Howard Maibach2)
BSAC


MEMS syringes offer possibilities of painlessly injecting suspensions of fine drug powders and biocompatible liquids through an array of hollow microneedles into the epidermis under the stratum corneum. The stratum corneum serves as the main barrier to transdermal penetration and drug delivery. It is important to find microneedle design parameters that will maximize skin penetration and delivery of drugs into the epidermal skin layer. Eventually, microneedles may be adapted for medical injection applications such as diabetes treatment and vaccines.

1BioEngineering
2UCSF

Email contact: boris@me


Confocal Nanofluidic SERS

Jaeyoun Kim and Gang Liu
(Professor Luke Lee1)
BSAC


In this project, we aim to implement an optical analysis system by incorporating nanofluidic chips, nano-structured surface enhanced Raman scattering substrate, and a miniaturized confocal scanning microscopy system. When implemented in a compact form, such a system will find great potential in table-top biochemical/celluar analysis and remote medicine.

1BioEngineering

Email contact: jaeyounk@berkeley.edu


Corona MEMS for Wide Study Area Air Particulate Monitoring

Beelee Chua
(Professor Norman Tien)
BSAC


The goals of this project are: (a) to miniaturize airborne particulates sizing and counting apparatus for ubiquitous deployment in air quality monitoring and epidemiological studies; (b) multitudes of such devices can be deployed over a wide study area (such as downtown Sacramento) to monitor the air quality in situ and generate air particulates spatial and temporal maps; (c) in-situ chemical composition analysis capability for NOx, CO and SO2; and (d) to extend the applications of a micro corona discharge device to micro ozone generator for biological sterilizing units, localized ESD control, and other EHD-based fluid actuation applications.

Email contact: bchua@ucdavis.edu


Coupling of Nanoresonators

Jeng-Wen Peter Chen
(Professor Roger T. Howe)
Berkeley Sensor and Actuator Center

Coupling-induced synchronization of two oscillators has been observed since 1665 [1]. Synchronization of many oscillators exhibits behavior that is sometimes challenging to analyze, but promise novel applications. In this context, we will investigate the different means of coupling nanoresonators, such as substrate mechanical coupling and amplified electrical coupling. We will explore techniques to modulate this coupling. Designs that exploit the coupling between an array of nanoresonators will be devised and fabricated.

[1]
The Royal Society Proceedings A, Vol. 458, 2002, pp. 563-579.

Email contact: jwpchen@eecs


DNA-Laden Flows in Microfluidic Systems

Shelly Gulati
(Professors Susan Muller1 and Dorian Liepmann2)
BSAC


The characterization of flows containing high concentrations of macromolecules is critical for the optimal design of microfluidic systems for biochemical analyses. Since the fluid flow behavior at the microscale differs from the macroscale, a simple scaling down of processes may be insufficient to elicit the same performance. This thereby motivates research directed toward the characterization of the microflow behavior of the biological macromolecule DNA, commonly used in biochemical assays. Digital Particle Image Velocimetry (DPIV) is used to measure the velocity fields of DNA-laden solution flow under microfluidic conditions. Deviations from Newtonian flow fields brought about by the viscoelastic fluid rheology, concentration effects, and conformational changes of the molecules are assessed for flows through a variety of microfluidic geometries.

1Chemical Engineering
2BioEngineering

Email contact: sgulati@socrates


DRIE Process Optimization for Very Smooth Sidewall Etch

Ning Chen and Matthew Wasilik
BSAC


The long term goal for this project is to develop a robust deep reactive ion etch process for a smooth sidewall through wafer etching, while maintaining a straight profile, good etch rate, and reasonable selectivity.

Email contact: ningc@eecs


Dedicated SiC MEMS LPCVD Reactor for Access through the DARPA MEMS Exchange Program

Christopher Roper
(Professors Roya Maboudian1 and Roger T. Howe)
BSAC


This project seeks to make Silicon Carbide thin films available to MEMS researchers and designers. A process developed in the Maboudian Lab at UC Berkeley which currently accommodates 2" wafers will be scaled up to accommodate 4" and 6" wafers. The new, larger LPCVD reactor will be in the UC Berkeley Microfabrication Lab. High quality poly-crystalline 3C-SiC films deposited at reasonable growth rates and with high uniformity will be sought. Doped SiC films will be deposited in addition to undoped films. Once films with high overall quality and repeatability are grown, the LPCVD tube will be released to the MEMS community.

1Chemical Engineering

Email contact: roper@berkeley.edu


Design of Controls for MEMS Adaptive Optics

Kuo-J Huang
(Professor Richard S. Muller)
BSAC


This research project investigates micromirrors used in the adaptive-optics system. Micromirrors have been used for adaptive-optics systems to correct the wavefront aberrations in the astronomical and vision science applications. The required number of micromirrors depends on the available motions of the actuator. For astronomical and vision science applications, the required number of micromirrors can be greatly reduced if the micromirrors are able to move in both rotational and translations motions rather than translational motion alone. The goal of our research project is to design the micromirrors with multiple motions and to integrate the micromirror with the control circuits.

Email contact: eastafrica_pofe@yahoo.com


Digitally Assisted Analog-to-Digital Converters

Dimitrios Katsis and Michael Douglas Scott
(Professor Bernhard Boser)
BSAC


The goal of this project is to develop enabling circuit techniques for increasing the compatibility of high performance analog-to-digital converters with deep sub-micron technologies.

Email contact: dkatsis@eecs


Disposable Multi Patch Clamps Using Planar Fludic Channels

Jeonggi Seo
(Professor Luke Lee1)
BSAC


Patch clamp techniques have had a profound impact on electrophysiology, playing a crucial role in the characterization of cellular ion channels. Traditionally, the technique was accomplished with a glass pipette positioned by a micromanipulator under a microscope. Even though the patch clamp technique has been improved, it is still laborious and requires precise micromanipulation of glass pipettes and skillful handling of the electrical sealing. In addition, the irreversible sealing between cell membranes and pipettes needs a new pipette for every new experiment. Because of these requirements, patch clamp techniques have been used less than fluorescence-based or other measurements in proteomics and drug developments where high-throughput measurements are required. An automated patch clamp setup for high-throughput measurements using disposable devices will eliminate the prohibitive time investment of traditional patch clamp, while maintaining its advantages against other measurements.

1BioEngineering

Email contact: seojohn@berkeley.edu


Effects of Boron Concentration on Si1-xGex Properties for Integrated MEMS Technology

Marie-Ange Naida Eyoum
(Professors Roger T. Howe and Tsu-Jae King Liu)
BSAC


Because of its low thermal budget which allows it to fabricate MEMS micromachined structures directly on top of electronics, SiGe MEMS technology remains very attracting for the monolithic integration of MEMS with CMOS. In this scheme, p+Ge would replace Silicon dioxide as the sacrificial layer while p+ SiGe would replace poly Silicon as the structural layer.

Email contact: meyoum@eecs


Electrophysiology Using a High-Density Microfluidic Array

Crisitian Ionescu-Zanetti and Jeonggi Seo
(Professor Luke Lee1)
BSAC


The fact that cellular ion channels are effective drug targets, coupled with the laboriousness of traditional patch clamp techniques, has created a need for hi-throughput electrophysiology platforms. Patch clamp based drug screening technology has been recently implemented by using microfabricated patch clamp designs that replace the traditional patch pipette with a pore in a silicon substrate. While successful at high-throughput measurements of channel activity, current devices have yet to achieve high densities of patched cells per unit volume and rely on robotically operated pipettes for reagent and cell delivery. Our aims are to develop a microfluidic based patch clamp device that features high density arrays for automated, high-throughput electrophysiology.

1BioEngineering

Email contact: ionescu@berkeley.edu


Fast Solution Exchange Microfluidic Device for Kinetic Analysis of Single Cells

Poorya Sabounchi
(Professor Luke Lee1)
BSAC


We are developing a novel fast solution exchange microfluidic device constructed from poly(dimethylsiloxane) for the kinetic analysis of single cells. The lateral cell trapping junctions enable hydrodynamic placement of a single cell from the bulk cell suspension and nano-fluidic injection sites enable fast and precise delivery of picoliter volume of reagents to that cell.

1BioEngineering

Email contact: poorya@me


Feasibility Study of a MEMS Viscous Rotary Engine Power System (VREPS)

Thomas Cauley
(Professor Albert Pisano)
BSAC


In this project an analytic, theoretical, and numerical study of the Viscous Rotary Engine Power System (VREPS) is completed. In addition, a proposed process flow for the fabrication of the VRESP using DRIE of silicon is developed. The design premise of the VREPS is to derive mechanical power from the surface viscous shearing forces developed by a pressure driven flow present between a rotating disk or annulus and a stationary housing. The resulting motion of the rotating disk or annulus is converted into electrical power by using an external permanent magnet, embedded nickel-iron magnetic circuits, and an external switched magnetic pole electric generator similar to the design proposed by M. Senesky for the UC Berkeley micro-Wankel Engine [1]. This project will examine the power output, isentropic efficiency, dynamic stability, and operating characteristics of the disk and annular viscous turbines. The viscous turbine is optimized for maximum isentropic efficiency using MATLAB numerical optimization routines. A unique triple-wafer micro-fabrication process for VREPS is also developed. The proposed design consists of a 250 µm thick, 3.4 mm OD / 2.4 mm ID annular rotor with embedded magnetic poles and four 10 µm driving channels on each side of the rotor. Electrical power is generated with a switched magnetic pole generator, external permanent magnet, and integrated magnetic circuits. Calculations with water predict an output power of 825 mW at an isentropic efficiency of 25% using a pressure drop of 5 MPa.

Email contact: icetrey@eecs


Floating Electro Mechanical Systems (FLEMS)

Jason Vaughn Clark
(Professors Sanjay Govindjee1, Kristofer Pister and James Demmel)
BSAC


The objectives of this project are to understand, characterize, and find useful applications for floating electromechanical systems. Various designs will be studied with a specialized finite element method with charge integral constraints.

1Civil Engineering

Email contact: jvclark@eecs


GHz Nano-Mechanical Resonators

Brian Bircumshaw
(Professor Albert Pisano)
BSAC


The objective of this project is to design, fabricate, and demonstrate nano-mechanical resonators (NMRs) with GHz natural frequencies. The Radial Bulk Annular Resonator (RBAR), our newest concept, represents a breakthrough in NMR design. Unlike its contemporaries, the RBAR can be arbitrarily sized for any given frequency. This provides design flexibility and increases the mechanical Q of the RBAR. Most importantly, the arbitrary sizing of the RBAR means tremendous reductions in the deviceys equivalent resistance, Req. This leads to drastically reduced insertion loss, lower power consumption, and lower unit cost. Theoretically, the RBAR enables:
  • < 100 µW power consumption per node
  • Ad-hoc "pico-cell" wireless sensor networks
  • Adaptive/secure telecom systems
  • High-scale integration of RF components
Recently, a poly-SiGe 200 MHz Bulk Longitudinal Resonator (BLR) was successfully fabricated by Emmanuel Quevy using the blade damascene process. The characteristics of the fabricated device correlate excellently with theoretical models, and demonstrates that electrostatic RF MEMS resonators can indeed be fabricated in a CMOS-compatible SiGe technology. Sub-100 nm gaps have also been successfully created in 2µm poly-Si films using a focused ion beam. Such a technique may prove useful for demonstration devices, quick-turn prototyping, and frequency tuning of fabricated devices.

Email contact: brianb@eecs


High-Performance MEMS Capacitors

Dan McCormick and Ming Li
(Professor Norman Tien)
BSAC


In this project, a set of MEMS based variable capacitors will be designed, fabricated, characterized and integrated into QUASAR's free-space capacitive EEG sensor for ultra-sensitive charge measurement.

Email contact: dmcc@eecs


Hybrid NanoElectroMechanical Transistors for High-Density, Low-Power, Low-Cost Computation and Memory

Donovan Lee1
(Professors Roger T. Howe and Tsu-Jae King)
IMT
Defense Advanced Research Projects Agency

As the minimum feature size of a transistor is scaled toward 10 nm and below, it becomes more and more difficult to maintain low leakage current, so that power consumption will be the primary challenge for nanometer-scale complementary metal-oxide-semiconductor (CMOS) technologies, particularly for portable electronics applications. Nanoelectromechanical (NEM) field-effect transistors (FETs) can potentially provide significant savings in energy as compared with conventional transistors. As an example, when high performance is needed, the gate electrode can be brought close to the semiconductor body of the transistor (either by moving the gate electrode, or by moving the body) to increase the capacitive coupling between the gate and the body, and thereby increase the transistor drive current in the ON state; and when low power consumption is needed, the gate electrode can be separated from the body to decrease the capacitive coupling between the gate and the body, and thereby decrease the transistor leakage current in the OFF state. The mechanical control of a transistor's threshold voltage can be leveraged for applications where power, density, and cost (rather than speed) are the primary considerations; examples of such applications include ultra-low-power computation, RF resonators, static memory, and non-volatile memory.

Figure 1
Figure 1: NEMFET structures will study applications in nanoactuation with resonators and memory structures.

Figure 2
Figure 2: The mechanically-gated NEMFET offers comparable drive performance across technology lines with a clear savings in static power consumption due to its dynamic Vt.


1Applied Science & Technology

More information: http://www.eecs.berkeley.edu/~dtlee
Email contact: dtlee@eecs


Ignition at the Microscale for Miniaturized Internal Combustion Engines

Bennett Sprague
(Professors Carlos Fernandez-Pello1 and Albert Pisano)
BSAC


This research project will determine the specific conditions under which fuel-air mixtures may be ignited at the microscale. In a research apparatus specifically designed for this purpose, premixed fuel and air charges will be ignited at various temperatures and pressures by an electric spark in the presence of quenching walls. The combination of temperature, pressure, and wall distance will be varied not only to simulate IC engine conditions, but also to explore the fundamental limits of spark ignition in combustion chambers with high surface area to volume ratios. Fuels to be considered include butane, propane, methanol, and gasoline.

1Mechanical Engineering

Email contact: sprasb@newton


Immunosensor

Turgut Sefket Aytur
(Professor Bernhard Boser)
BSAC


The goal of this research is to develop and verify diagnostic assays for infectious diseases currently presenting significant threats to public health, including Dengue, Malaria, and HIV. The reporting elements in these assays are paramagnetic beads, which are detected using a CMOS based platform. Our goal is to demonstrate improved protocol simplicity compared to ELISA, the current immunoassay standard, with special emphasis on the applicability of the assay in a point of care or at home setting where the advents of a research laboratory are not available.

Email contact: turi@eecs


In Vitro Biosilica Formation Using Micro/Nanoemulsion Templating

Frank Zendejas
(Professors Jay D. Keasling1 and Roger T. Howe)
BSAC


Diatoms are unicellular algae that exhibit exquisite silica cell walls, frustules, made of amorphous silica. Research has shown that diatoms are capable of controlled precipitation of silica during cell division within a specialized membrane called the silica deposition vesicle (SDV). The precipitated silica forms the new shell for the daughter cell. It has been postulated that the diatom SDV contains an emulsion of organic macromolecules arranged in a regular pattern which serve as a template onto which silica is precipitated. Our goal of this project is to use a specially designed emulsification microreaction chamber to gain insight on biosilica formation in vitro at room temperature and near-neutral pH using micro/nanoemulsion templating with synthetic catalyst and diatom-derived silaffins to create micro- and nanoporous silica.

1Chemical Engineering

Email contact: zendejas@eecs


Incremental Network Programming

Jaein Jeong
(Professor Kristofer Pister)
BSAC


We present an incremental network programming mechanism which reprograms wireless sensors quickly by transmitting the incremental changes for the new program version.

Email contact: jaein@eecs


Integrated Nano Mechanically-Regulated Atomic Clock: Thin Film Magnetic Shielding Alloy

Carolyn White
(Professor Albert Pisano)
BSAC


An integrated, nano mechanically-regulated atomic clock will be designed, fabricated, and evaluated to reduce the size, mass, and power consumption and enable use on portable platforms. This particular project will specifically develop a thin film shield for modulation of a magnetic field.

Email contact: whitecd@newton


Integration of NEMS and MEMS by Localized Growth of Nanowires

Ongi Englander
(Professor Liwei Lin1)
BSAC


Integrated manufacturing of nano-to-micro systems is critical for the practical applications of nanotechnology. This research project aims (1) to develop and characterize an integrated manufacturing process to connect nanostructures with micro scale systems and (2) to utilize the integrated structure for practical sensing applications.

1Mechanical Engineering

Email contact: ongi@me


Liquid Fuel Injection System for Mini Rotary Engines

Sang-Won Park
(Professors Carlos Fernandez-Pello1 and Albert Pisano)
BSAC


The goal of this research is to develop a fuel injection system which delivers the desired ratio of air/fuel mixture to 367/1500 mm3 rotary engines.

1Mechanical Engineering

Email contact: intropia@eecs


Liquid Fueled MEMS Enabled 367 and 1,500 mm3 Rotary Engine Power System (REPS)

Mitchell Swanger, Sang-won Park, Bennett Sprague, Ronda Ropes and David Walther
(Professors Carlos Fernandez-Pello1 and Albert Pisano)
BSAC


The goal of the 367 cu.mm and 1,500 cu.mm Rotary Engine Power System (REPS) project is to develop and fabricate a small scale power generation device providing comparably high specific energy density. Power will be generated by a liquid hydrocarbon fueled Wankel rotary engine. Several MEMS systems are being devloped to increase system efficiency.

1Mechanical Engineering

Email contact: mswanger@eecs


Location Estimation Using RF Time of Flight

Steven Michael Lanzisera
(Professor Kristofer Pister)
BSAC


An enabling technology for large scale sensor networks is the ability to determine a sensor's location after deployment. Some applications, such as inventory management, use sensors that move regularly, and this spatial information is crucial to their 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 performing a cross correlation between a received and an expected signal. Using the entire correlation signal rather than just the peaks allows the use of techniques that reject interfering signals better than in some simpler schemes, but special effort must be made to avoid increasing the cost of the system. The end goal is to provide low power, accurate, self-contained, ad hoc localization to mobile sensor nodes.

Email contact: slanzise@eecs


MEMS Design Synthesis and Optimization

Ying Zhang and Raffi Kamalian
(Professor Alice Agogino1)
National Science Foundation

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. So far, a hierarchical MEMS synthesis and optimization architecture has been developed, which integrates an object-oriented component library with a MEMS simulation tool and two levels of optimization: global genetic algorithms (GA) and local gradient-based refinement. Test resonators generated from the GA process with the SUGAR simulation tool as a simulation engine have been fabricated and characterized, which validated the GA synthesis algorithm. The best GA designs have been refined using gradient optimization technique. The performance of some designs could be improved up to 15%. In the design library, an object-oriented data structure is used to represent hierarchical levels of elements and their connectivity. Additionally, all elements encapsulate instructions and restrictions for genetic operations (mutation, crossover). The parameterized component library includes distinct low-level functional elements and high level clusters, which are composed of primitive elements. This component library will be further developed into a MEMS design case library.

1Mechanical Engineering

Email contact: yzh@berkeley.edu


MEMS Integrable Temperature Sensor

Chao-chih Hsu
(Professor Richard S. Muller)
BSAC


Temperature sensors have a wide range of applications. They are needed in all fields of research ranging from chemistry and biology to electrical engineering and mechanical engineering. As miniaturization takes steps into micro-scale, the need for obtaining thermal information becomes more prevalent. Our goal in this project aims to create a micro temperature sensor that can be integrated into the MEMS structures.

Email contact: ghsu@uclink


MEMS Microswitch for High-Voltage Applications

Fabian Strong
(Professor Norman Tien)
BSAC


A microswitch utilizing thermoelectric MEMS actuators will be designed, fabricated, and characterized. The switch is intended to switch >500 VDC with over 100 gigaohms off-state resistance. It will replace external mechanical relays in high-voltage circuits, without sacrificing high isolation levels. The device will eventually be configured into an array of switches for dense switching applications.

Email contact: fwstrong@ucdavis.edu


MEMS REPS: Assembly of a MEMS Compressed Air Expander Unit

Jose Rosario-Rosario
(Professor Albert Pisano)
BSAC


The objective of this research is to demonstrate power generation at the micro-scale using a compressed air expander. The setup includes a rotor with embedded magnetic poles spinning inside a housing, cover plates with stationary gear, fluidic access porting plates, and an integrated functional AC electricity generator. The means for actuation of the system will be using compressed air as the driving force. The ultimate goal of the demonstration task is to complete and deliver working units to the Defense Advanced Research Projects Agency (DARPA). Proper assembly techniques are being developed to integrate all the parts that make up a functional compressed air engine.

Email contact: jrosario@eecs


MEMS REPS: MEMS Fuel Vapor Delivery by Flow Rectification

Josh Heppner
(Professor Albert Pisano)
BSAC


In this project, a MEMS fuel delivery system is to be designed, fabricated, characterized, and then integrated into a rotary engine called MEMS REPS.

Email contact: jheppner@newton


MEMS RF Switch with Liquid Gallium Contacts

Qingquan Andy Liu
(Professor Norman Tien)
BSAC


A self-healing MEMS RF switch, which utilizes liquid gallium contacts to take the place of the traditional metal-to-metal hard contacts, is proposed in this project. Electrostatic actuation is utilized to actuate the silicon nitride diaphragm. When the upper electrode is pulled down by the electrostatic actuator, small droplets of liquid gallium provide a deformable electrical interface between the upper and lower electrodes. The loss of the gallium droplets can be avoided due to the unwettability of the material surrounding the contact areas as well as proper geometric design of the wetting patterns and ambient switching environment.

Email contact: qqliu@ucdavis


MEMS RF-Interrogated Biosensor (MIB)

Sebastien Payen
(Professor Albert Pisano)
BSAC


We outline an interdisciplinary research program bridging the domains of biochemistry, radiofrequency I.D. tags, telecommunications, and intelligent network interface. In this project we describe a MEMS RF-Interrogated Biosensor (MIB). The MIB is a microfabricated structure that comprises a microneedle, a functionalized gel, a tuned tank oscillator circuit, and a miniature antenna. The MIB utilizes volume changes in the functionalized polymer (hydrogel) in order to change mechanically the tuning of the simple tank oscillator circuit. The functionalized polymer changes in volume in response to changes in the biological organism in which the microneedle is inserted. Changes in the tank oscillator circuit can be determined by remote RF interrogation, using a passive scheme in which the need for a local power source on the MIB is made unnecessary.

Email contact: spayen@me


MEMS Rotary Engine Power System (MEMS REPS)

David Walther
(Professor Albert Pisano)
BSAC


The goal of the MEMS Rotary Engine Power System (MEMS REPS) is to develop an autonomous, commercially viable, portable power system based on an integrated power generator and rotary internal combustion engine. This engine is designed to generate a continuous power output of 100 mW. The design also allows for rapid field implementation in a variety of applications requiring localized power generation in the range of 10-500 mW. Applications include interconnected sensor networks or land warrior power supplies. The MEMS Rotary Engine Power System program under development at UCB incorporates many sub-projects to address much of the ancillary equipment necessary in order to more fully develop thermally driven power supplies at the micro-scale. These development projects include an integrated electric generator, fuel delivery system, SiC surface coatings, and thermal packaging.

Email contact: walther@eecs


MEMS Rotary Engine Power System/Electro-Magnetic Valve

Eri Takahashi
(Professor Albert Pisano)
BSAC


The objective of this research is to develop a valve with an actuator for fuel delivery system. To be integrated into MEMS Smart Plate, all-silicon planar structure is desirable.

Email contact: eritaka@eecs


MEMS Rotary Engine Power System/Engine Fabrication

Fabian Martinez
(Professor Albert Pisano)
BSAC


The goal of the MEMS REPS/engine fabrication is to fabricate a rotary engine within tolerances predetermined through numerical modeling.

Email contact: fabian@eecs


MEMS Rotary Engine Power System/Engine Fluid Management System

Brenda Haendler
(Professor Albert Pisano)
BSAC


A MEMS fuel vaporization and injection system for the Wankel engine is being designed, fabricated and characterized with the long-range goal of incorporating this system as the engineys intake manifold. To attain this goal it is essential to gain an understanding of microscale evaporation, namely the phase eruption phenomena, of liquid hydrocarbon fuels in microchannels.

Email contact: brendler@eecs


MEMS Rotary Engine Power System/Integrated Generator

Matthew Kurt Senesky
(Professors Albert Pisano and Seth R. Sanders)
BSAC


The goal of the MEMS REPS integrated generator project is to design and fabricate a millimeter-scale electric machine to generate power from the mechanical torque of a liquid hydrocarbon fueled MEMS rotary engine.

Email contact: senesky@eecs


MEMS Rotary Engine Power System/Soft Magnetic Pole Integration

Debbie Jones
(Professor Albert Pisano)
BSAC


The goal of this research is to electroform ultra thick ferromagnetic structures into a silicon mold patterned with DRIE.

Email contact: dgjones@eecs


MEMS Strain Gauge on Steel

Anand Jog
(Professor Albert Pisano)
BSAC


The research and development proposed herein will improve the operating characteristics of traditional machine elements and the applications to which they contribute through the development and application of MEMS microstructures in two major categories. First, we will develop low-cost MEMS strain-sensing modules and the means to rapidly bond them to steel and other structures in large quantities. In addition to wire-based solutions, we will also develop modules for wireless data telemetry and power coupling to enable total systems-level solutions for the MEMS sensor modules. This will open the door toward providing low-cost load sensing for many applications. MEMS-based strain sensors offer much smaller gauge length (< 500 mm) than commercially available foil-type gauges.

Email contact: jog@eecs


MEMS Strain Gauge on Steel: Capacitance Sensor Design and Fabrication

Babak Jamshidi
(Professor Albert Pisano)
BSAC


The main objective of the project is the design and fabrication of a capacitance strain gauge capable of measuring micro-strain to improve the operating characteristics of steel substrates in the applications to which they contribute. Temperature and aging have a relatively small influence on the sensitivity and precision of this type of sensor, where the traditional strain gauges always have this issue as a major concern.

There have been three major goals set up for this project. 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 (10e-6) with a gauge length no greater than 1 mm and also operates by in-situ mounting on pre-existing, minimally treated steel substrates. In addition, the strain gauge has a dynamic range of at least 1000 Hz and maintains enough sensitivity and linearity over a range of temperatures and environmental conditions. In particular, this project is an examine for the use of a capacitor to transduce strain into an electrical signal via capacitive sensing.

The main contributions of this project to the industry are in two major categories of low-cost load sensing and overload protection as well as lubrication and heat transfer improvement.

To fabricate a strain sensor capable of measuring micro-strain (10e-6) with a gauge length no greater then 1 mm, the sensor will be capable of in-situ mounting on pre-existing, minimally treated steel substrates. In addition, the sensor will also have a dynamic range of at least 0-1000 Hz, and maintain sensitivity and linearity over a range of temperatures and environmental conditions. In particular, this project is examining the use of a capacitor to transduce strain into a electrical signal via capacitive sensing (by parallel plates).

Email contact: jamshidi@eecs


MEMS Strain Gauge on Steel: Electromechanical Analyses of Strain Sensors

Todd Lauderdale and Wayne Huang
(Professors Oliver O'Reilly1 and Albert Pisano)
BSAC


In support of a project underway to develop a MEMS strain gauge for placement on a steel substrate, we are modeling the dynamics of a single-crystal silicon double-ended tuning fork (DETF) resonator. With the resonant sensor, the strain of the steel substrate will be determined by measuring the changes in the resonant frequencies of the DETF. We hope to understand how the resonant frequencies of the DETF vary under many effects including axial and non-axial strain of the tines of the DETF, geometric variations, thermal gradients, electromagnetic forces, varying material properties, and different methods of exciting the DETF into resonance.

1Mechanical Engineering

Email contact: wayne.huang@juno.com


MEMS Strain Gauge on Steel: Packaging

Robert Azevedo
(Professor Albert Pisano)
BSAC


The overall project aims to design a MEMS strain gauge that can be bonded directly to steel and accurately measure strain in small strain fields (gauge length of 1 mm or less). The objective of this project is to produce a package that can provide a hermetic seal while still transmitting strain to the strain sensing elements. This is novel since standard electronics packaging tries to reduce transmitted strain. The aim is to create an elastic package that can be integrated with both a micromachined strain gauge and CMOS chip.

Email contact: azevedo@eecs


MEMS Strain Gauge on Steel: Rapid Bonding of MEMS Strain Gauge to Steel

Brian Sosnowchik
(Professors Liwei Lin1 and Albert Pisano)
BSAC


A rapid and reliable bonding method is needed to bond MEMS strain gauges to steel. The MEMS strain gauge is to be bonded to the manufactured steel after all other steel treatment steps have been completed; hence the bonding method must be kept at a low temperature to prevent any thermal damage to the steel composition. In addition, the bonding method must not introduce high residual strains, which would cause error in strain gauge measurements. The strain gauge to steel bond must also have the ability to survive several years in a wide working temperature range (-20 C to 150 C) in an oily environment. Rapid localized induction heating and ultrasonic bonding methods are being investigated as possible solutions.

1Mechanical Engineering

Email contact: bdsosnow@me


MEMS Strain Gauge on Steel: Selective Strain Isolation

I-yang Chen
(Professor Albert Pisano)
BSAC


This project aims to design strain isolation trenches into the sensor package such that strain may be selectively isolated in specific sections, and along specific directions thereby reducing the cross-axis sensitivity of the strain sensor. The particular sensor package is an encapsulated, resonating MEMS strain gauge specially designed to be direct-mounted on steel with a strain resolution of 0.1 µm-strain. To this end, a strain isolation structure has been designed that rejects cross-axis strain while still maintaining axial strain fidelity.

Email contact: iychen@eecs


MEMS Strain Gauges on Steel: Electronic Interfaces for Resonant Sensors

Kenneth Edward Wojciechowski
(Professor Bernhard Boser)
BSAC


The objective of this research is to develop electronic interface circuits to measure strain in automobile machine elements with a silicon micromachined resonant sensor. The strain sensor is required to have a resolution of 0.1 microstrain over a range of +/- 1000 microstrain and a measurement bandwidth of 10 kHz. The dimensions of the strained areas in the bearings are on the order of 100-200 microns and therefore gauge lengths of the strain sensor must be in this range. The smallest commercially available strain sensors have gauge lengths of around 1 mm are too large and thus micro-machined strain gauges are an attractive solution to this problem. Double-ended tuning fork (DETF) resonant sensors are a natural choice for this application because they have the potential to meet the size, resolution, and bandwidth requirements described above. When subjected to an axial strain, the DETF's length changes resulting in a change in its resonant frequency and or period. Our research will concentrate on the methods of measuring the change in resonant frequency and therefore strain.

Email contact: kenwoj@eecs


MEMS Synthesis Using Stochastic Optimization

Raffi Kamalian and Ying Zhang
(Professors Alice Agogino1, Kristofer Pister and James Demmel)
BSAC


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. So far, several design synthesis examples have been solved using stochastic optimization techniques with the SUGAR simulation tool as a simulation engine. Synthesized designs have been fabricated in order to characterize their performance and validate the synthesis algorithm. The research will be framed within a larger research program for developing tools for the synthesis of MEMS suspensions and actuators.

1Mechanical Engineering

Email contact: raffi@me


MEMS Synthesis Using Stochastic Optimization

David G Garmire and Jason Clark
(Professors Sanjay Govindjee1, Kristofer Pister and James Demmel)
BSAC


Practical analysis techniques to accurately measure geometric, dynamic, and material properties of MEMS will be developed. Analytical methods and test structures will be made to extract over two dozen properties by electric probing in a minimal chip area. Geometric properties will include fabrication error with respect to layout geometry such as beam widths, gap spacings, etch holes, and beam lengths. Dynamic properties will include mass, damping, stiffness, bulk compliance, quality factor, exponential damping factor, displacement amplitude, velocity amplitude, comb drive force, and fringing field factor. Material properties will include Young's modulus, residual stress, shear modulus, Poisson's ratio, and material density. These techniques will differ from those currently available in practicality and that no geometric, dynamic, or material property values are presumed. Only electrically-based measurements (i.e., capacitance, voltage) will be required. We will use the measured properties in CAD models to predict the performance of more complex designs.

1Civil Engineering

Email contact: jvclark@eecs


Mechanical Analysis of SiC for Use as a High Temperature, Pressurized Micro Reactor

Jonathan Rheaume
(Professor Albert Pisano)
BSAC


A high temperature pressurized micro reactor is highly desireable for several applications. A study of SiC (silicon carbide) as the structural material was undertaken to determine the suitability of using deposited SiC for reactions such as steam reforming.

Email contact: jrheaume@me


Micro Plastic Injection Molding: Microneedle Molding

Julian Lippmann
(Professor Albert Pisano)
BSAC


This project along with Emil Geiger's project (also in this chapter) investigates the manufacturing and integration of µm scale plastic parts through injection molding. Emphasis is placed on developing robust, but simple fabrication methods capable of molding microneedles: 100 µm x 100 µm hollow tubes. The issues to be addressed span the micro and meso regimes. At the microscale effort focuses on creating accurate, robust molds that can deliver MEMS scale needles. On the mesoscale, Plastic injection materials and processes are being investigated to yield optimum results. Current results: rods of 100 µm x 100 µm x 1 mm, rods of 100 µm x 200 µm x 3.5 mm, and protoneedles 100 µm x 200 µm x 200 µm.

Email contact: lippmann@newton


Micro Plastic Injection Molding: Packaging of Discrete Micro Fluidic Components

Emil Geiger
(Professor Albert Pisano)
BSAC


The goal of this project is to develop a single-step method for assembling and encapsulating discrete micro fluidic components in which injection-molded plastic secures the fluidic and electrical interconnects. All of the necessary components for the chamber are loose assembled in a plastic-injection mold and subsequently packaged, encapsulated, and sealed in one molding step. These components include a silicon/Pyrex micro fluidic component, electrical leads, and small-gauge stainless steel fluidic headers. This approach delivers fully integrated micro fluidic components with 1) zero dead volume, 2) low electrical contact resistance (<1 Ω), 3) low compliance, in-plane fluid interconnects, and 4) small overall dimensions (7.5 mm x 4 mm x 3 mm) conforming to the Dual In-Line Package (DIP) standard. Ultimately, a variety of micro fluidic components, such as pumps, valves and mixers, could be packaged this way and subsequently assembled via "pick and place" into a system.

Email contact: ejgeiger@eecs


Microflow Control Using Thermally Responsive Triblock Copolymers

Boris Stoeber
(Professors Dorian Liepmann1 and Susan Muller2)
BSAC


Dilute aqueous solutions of poly(ethylene oxide)x-poly(propylene oxide)y-poly(ethylene oxide)x triblock copolymers undergo reversible gel formation at elevated temperatures. This effect can be effectively used for active and passive flow control in microfluidic devices, where the gel phase can block the flow channel partially or entirely. Heat transfer occurs fast through the typically small width of a microchannel. The dynamic response of the polymer is an important parameter for the design of microflow valves and will be investigated.

1BioEngineering
2Chemical Engineering

Email contact: boris@me


Microfluid Integrated Nano-Scale Biological Cell Probes

Jesse Herrick
(Professor Albert Pisano)
BSAC


Biologists at Lawrence Livermore National Laboratory are performing rigorous cell research in which standard cell analysis techniques have provided limited information. The current analysis techniques are typically external observation based, however, it has become apparent that internal observation techniques may be required for a better and more thorough understanding of cellular function. The devices under investigation in this collaborative project between LLNL and UC Berkeley aim to help fulfill this need. The devices, which are based on both MEMS and NEMS technologies, will be designed, fabricated, optimized, and implemented for cell research.

Email contact: herrick@eecs


Microfluidic Cell Culture Array

Philip Lee, Paul Hung and Robert Lin
(Professor Luke Lee1)
BSAC


The investigation of biological processes on the cellular level is becoming increasingly important for medical and bioengineering purposes. We have learned from genomics and proteomics that a vast amount of molecular information is integrated on the cell level. However, current technology is limited in the ability to assay cellular responses to stimuli in high throughput format. Specifically, a standardized platform to perform array experiments on the laboratory scale is needed to help scientists unravel the complexities of eukaryotic cellular behavior. To this end, we are developing a microfluidic cell culture array as an inexpensive, flexible system for providing a controlled cell growth and analysis microenvironment.

1BioEngineering

Email contact: pjlee@berkeley.edu


Microfluidic Cellular Manipulation for Sample Preparation Microsystems

Dino Di Carlo and Cristian Ionescu-Zanetti
(Professor Luke Lee1)
BSAC


Our long range goals are to understand and control forces on cells in microfluidic devices to manipulate cells for biotechnology applications. This includes cell lysis for mTAS applications and poration for gene and large molecule delivery.

1BioEngineering

Email contact: ddicarlo@socrates


Microfluidic System for Cryogenically Storing and Reviving Biological Cells

Natalya Etina
(Professor Albert Pisano)
BSAC


The project goal is the design, fabrication, and testing of the structural component in the cell-based environmental monitoring sensor. The structure will consist of a microfabricated array of cell wells as well as multi-level microfluidic manifolds to carry the necessary fluids to these wells. While the cells are being stored, liquid nitrogen would flow through channels around the wells and bring the cells to cryogenic temperatures. At room temperature, the functioning cells would be supplied with food and have their waste removed through two separate fluid lines under the wells. The fluids in these lines would be driven into and out of the wells using pressure driven flow across a porous silicon membrane, which will prevent the cells from leaving the well. The eventual goal of this device is for individual wells to be thawed for study while all other wells remain frozen.

Email contact: netina@eecs


Micromachined Photosynthetic Fuel Cells

Kien-Bang Lam
(Professor Liwei Lin1)
BSAC


The project aims to develop micromachined biological photosynthetic fuel cells (uPFC) for two classes of devices: (1) micro-scale mobile sensors and micro communication devices and (2) nano-scale molecular motors such as ATP synthase and myosin. For the first class of devices, the uPFCs are competing technologies to other micro power sources such as micro batteries, micro engines, and thin-film solar cells. However, for the second class, the uPFC is a pioneering effort to engineer power sources for future molecular and biomimetic devices.

1Mechanical Engineering

Email contact: kblam@me


Microrobots

Sarah Elizabeth Bergbreiter and Anita Flynn
(Professor Kristofer Pister)
BSAC


The goal of this research is to create a class of articulated autonomous microrobots with a volume of less than 1 cm3.

We previously reported an autonomous micromachined silicon legged robot which has taken its first steps. The body of the robot is fabricated in a planarized silicon-on-insulator (SOI), two-layer polysilicon process and is 8 mm x 4 mm x 0.3 mm in size. The complete robot has two additional ICs, a solar cell and high voltage buffer chip along with the low-voltage CMOS chip for sequencing. In addition to the autonomous microrobot, we have demonstrated a 2 degree-of-freedom (DOF) leg and a reversible inchworm motor operated with an off-board controller. The leg, 1 mm in length, sweeps an area of more than 0.1 mm2. In frontwards operation, the foot of the leg has exerted from 6 µN to 33 µN of vertical force, depending on the angle of the joints. Endurance tests have shown that the leg is visually undamaged after 60,000 full leg sweeps for 16.5 hours of operation (~10 million inchworm cycles).

In the past six months, work has been focused on new designs for a high-voltage polymer fabrication process in conjunction with Micropropulsion and SRI. A high voltage (several thousand volts) is applied across a dielectric elastomer material using grease-based electrodes. Since these electrodes stretch with the material, this actuation causes the material to increase in size over 100%. By shaping the polymer in different ways, it is possible to achieve legged walking or hopping motion on centimeter-scale robots. Work has also been focused on examining new mechanisms and processes for jumping and walking microrobots in silicon.

Email contact: sbergbre@eecs


Minimally Invasive MEMS-based Optical Coherence Tomography for in-vivo Imaging

Dan McCormick and Avinash Kane
(Professor Norman Tien)
BSAC


The objective of this work is to develop a miniature MEMS based probe for high speed, high resolution, in-vivo optical coherence tomography (OCT) imaging. The realization of a small scale OCT system with high spatial and velocity resolution as well as rapid image acquisition rates has numerous potential applications in medicine, including real-time optical biopsies.

Email contact: dmcc@eecs


Monolithic Piezoelectrically-Actuated MEMS Tunable VCSEL

Michael Chung-Yi Huang and Benjamin Cheng1
(Professors Constance Chang-Hasnain and Albert Pisano)
BSAC


A novel piezoelectrically-actuated microelectromechanical system (MEMS) tunable vertical-cavity surface emitting laser (VCSEL) is to be designed, fabricated and evaluated to provide improved wavelength control with lower power supply voltages and reduced external losses. Applications include signal routing and switching in modern optical communication networks and VCSEL-pumped atomic clocks. The project will focus on device design, modeling and monolithic integration of piezoelectric controlled MEMS with VCSEL for wavelength control.

1Mechanical Engineering

Email contact: mcyh@eecs


Multidirectional Force and Torque Sensor

Mansoor Nasir
(Professor Dorian Liepmann1)
BSAC


In order to understand the unsteady aerodynamics of insect flight, a sensor has been fabricated that measures the small multidirectional forces generated by fruit flies during tethered flight while simultaneously supporting it inside a LED flight simulator arena. This sensor will provide quantitative data that will help to better understand sensorimotor mechanisms of flight control in flying insects.

1BioEngineering

Email contact: mnasir@socrates


Nano Photodiodes

Lei Luo
(Professor Liwei Lin1)
BSAC


The goal of this project is the development of single ZnO nanowire photodiodes for applications in nano-optics and bio-detection.

1Mechanical Engineering

Email contact: leiluo@me


Nano-Getters for MEMS Applications

Daoheng Sun and Dane Christensen
(Professor Liwei Lin1)
BSAC


A high vacuum inside a micro-cavity is hoped to be obtained and maintained for the lifetime of a MEMS. This project will supply design rules of getter dimensions in MEMS packaging by exploring the relationships of the residual gas pressure and its variety in a cavity with (1) the different getter materials, such as Ti, Zr, V, and their mixture, and (2) the surface area, thickness, and amount of the getter deposited respectively. We will use multi-times, activating the getter by means of localized heating to improve the efficiency of it. We will develop the nano-getter with high porosity and large surface area. We will design and fabricate the nano-ion-pump to adsorb inert gases such as Ar and He. We will begin design and fabrication of the nano- or micro-vacuum gauge to monitor the vacuum changing inside the micro-cavity because of the effect of getter, outgassing and leakage.

1Mechanical Engineering

Email contact: sundh@berkeley.edu


Nano-Probes for Biological Cell Monitoring Fabricated by Nanoimprinting Lithography (NIL)

Inkyu Park
(Professor Albert Pisano)
BSAC


A biological cell-based sensor is being developed for the monitoring of enviornmental changes based on the electrical potential changes of the cells. In this project, we specifically investigate the effects of a high frequency electromagnetic field on the biological cells. In this sensor, several components are integrated: cryogenic preservation of cells for their prolonged usage, RF source for localized irradiation of cells, and nano-probe tips for the minimally invasive measurement of electrical potential within the cell. In particular, a nano-probe tip will be fabricated using the nanoimprinting lithography (NIL) and integrated with microfabricated micro-probe device.

Email contact: inkyu@eecs


Nanofabrication Technology for Large Area Nanowires and Nanodots: Spacer and Nanoimprint Lithography

Sunghoon Kwon1 and Xiaoming Yan2
(Professor Jeffrey Bokor)
Double imprint project


High throughput patterning of sub-100 nm periodic features on surfaces has been of great interest for a number of scientific and engineering applications, such as sensors, soft X-ray optical device components, electronic circuit elements, or catalysts. In chemical and physical applications such as catalysis and sensors, low-cost periodic patterning is required rather than the arbitrary-shape, patterning capability of e-beam lithography. To satisfy this requirement and overcome the low throughput and high cost of electron beam lithography, a residual conformal film on the side wall of a photolithographically-defined pattern (a so-called "spacer") has been used to generate nanoscopic line features, with a line width that is well controlled by the deposited film thickness [1,2]. If this spacer lithography is used n times in succession, 2n lines can be generated from a single lithographically defined line. With nanoimprint technology, Pt nanowires and Pt nanoparticles can be fabricated by the spacer lithogrpahy for catalysts and nanowires composed of other materials can be used for chemical and biosensors. However, these techniques are limited to closed loop shaped line patterns and are not able to produce discrete dot patterns since spacers are formed along the side walls of the original features. In this work, we develop an advanced method for the conversion of spacer nanowires into dots by Mold-To-Mold Cross Imprint (MTMCI) based on the spacer and nanoimprint lithogrphy. First, 15 nm wide silicon nanowire molds with 250 nm pitch were fabricated by deep UV lithography and spacer lithography. Then the conversion of the wire pattern into a dot pattern by redefining a nanowire imprint mold with another nanowire imprint mold with perpendicular arrangement. This silicon nanodot array is to be used as an imprint mold for patterning well ordered nanoscopic metal islands with uniform size distribution. These, in turn, are useful for catalyst research or surface enhanced Raman spectroscopy.

[1]
Y. K. Choi, T. J. King, and C. Hu, IEEE Electron. Device Lett., 2002, Vol. 46, pp. 1595.
[2]
Y. K. Choi, J. Zhu, J. Grunes, J. Bokor, and G. A. Somorjay, J. Phys. Chem. B, 2003, Vol. 107, pp. 3340.
[3]
S. Kwon, X. Yan, A. Contreras, G. A. Somorjai, J. A. Liddle, and J. Bokor, NNT04, 2004.
1Lawrence Berkeley National Laboratory
2Lawrence Berkeley National Laboratory

Email contact: skwon@lbl.gov


Nanogap Junction Capacitors For Biomolecular Detection

Dino Di Carlo and Joshua Nevill
(Professor Luke Lee1)
BSAC


The goal of this project is to develop a sensitive, label-free detection technology for biomolecular interactions using a format that can be made highly parallel and disposable. Nanogap sensors enable direct detection, without the need for fluorescent labeling, by using dielectric spectroscopy.

1BioEngineering

Email contact: ddicarlo@socrates


Nanorainbow Genomics/Proteomics Chip

Gang Liu
(Professor Luke Lee1)
BSAC


Based on the integrated plasmonic nanowire array, a genomics/proteomics microchip will be built to identify unlabeled oligonucleotides and study the protein-protein interaction in a high-density array format. The multiplexing detection and high-throughput will be realized.

1BioEngineering

Email contact: ganglliu@berkeley.edu


Nanowire-Coupled Bulk-Mode Resonators for Electromechanical Mass Detection

Noel Arellano
(Professor Roger T. Howe)
BSAC


We are developing fabrication processes to create top down nanowire coupled bulk-mode resonators. The critical dimensions will be defined using a combination of Deep UV lithography, photoresist ashing techniques, and thermal oxidation. Nanowires will be used as mechanical elements to demonstrate low velocity coupling for MEMS filters. They will also be employed as conductive coupling channels between MEMS resonators to detect resonance based on mobility enhancement of electrons resulting from an axial strain in silicon. We aim to create resonators that stretch the coupling nanowire into tension to enhance the current flowing through the wire. As the project evolves we will incorporate bottom-up Vapor Liquid Solid nanowire fabrication to create the lateral coupling elements.

Email contact: arellano@eecs


Non-Dispersive IR Gas Detection with a MEMS Scanning Mirror and Linear Variable Filter

J. Provine
(Professors David Horsley1 and Norman Tien)
BSAC


This project seeks to develop an Infra-Red (IR) gas detector that can tune over a wide frequency range for the detection of various gases such as CO2, CO, and CH4 (methane). The system incorporates a MEMS scanning mirror and various additional optical elements including a Linear Variable Filter (LVF) and parabolic mirrors to achieve the desired system.

1UC Davis

Email contact: jprovine@ece.cornell.edu


Novel SiGe Processes for Electrostatically Actuated MEMS Resonators

Carrie Wing-Zin Low
(Professor Roger T. Howe)
BSAC


The goal of this project is to optimize the SiGe film deposition process for post-CMOS radio frequency MEMS resonators. Low thermal budget, small tensile stress, low strain gradient, high quality factor are the requirements for the SiGe film. In addition, a controllable and repeatable process for mass production is desired.

Email contact: wlow@eecs


On-Chip Cryopreservation of Cells

Sha Li1
(Professor Liwei Lin2)
BSAC


The goal of this project is to develop an on-chip cryopreservation of cells with potential applications to sperm or embryo preservation, single cell manipulation, or lab-on-a-chip.

1Mechanical Engineering
2Mechanical Engineering

Email contact: shali@me


Photonic Band Gap Infrared Sensors

Jack Skinner and J. Provine
(Professor David Horsley1)
BSAC


Infrared (IR) sensors are typically used for gas detection, thermal imaging, motion sensing, and temperature measurement. A narrow-band optical filter is often used to confine radiation intensity measurement to a specific set of IR wavelengths. The current project seeks to make the IR sensor inherently narrow band by creating photonic band gaps in the surface of the detector with a two-dimensional photonic lattice. This research will decrease sensor size and improve sensor functionality, thus increasing the application space for narrow-band IR sensors.

1UC Davis

Email contact: jlskinner@ucdavis.edu


Piezoelectric Bulk Mode Resonators for RF Filtering

Philip Stephanou
(Professor Albert Pisano)
BSAC


The goal of this project is to develop micro-mechanical resonators for radio-frequency (RF) signal processing. We are currently exploring the use of thin-film piezoelectric plates driven in bulk modes of vibration. The envisioned resonator must demonstrate a high mechanical quality factor (Q) and low insertion loss for improved filter selectivity and minimal power consumption.

Email contact: stephp@newton


Portable Monitor for Airborne Particles

Justin Phelps Black
(Professors Mike Apte1 and Richard M. White)
BSAC


This project involves development of a MEMS-based instrument for particle exposure assessment (MEMS-PEA). The instrument measures and differentiates fine particulate matter (PM) concentrations from such sources as diesel vehicles, woodsmoke, and environmental tobacco smoke.

1LBNL

Email contact: jblack@eecs


Post-Process of GHz-Range SiGe Resonators over Standard RF CMOS Circuitry for Transceiver Applications

Emmanuel Quevy
(Professors Roger T. Howe and Tsu-Jae King Liu)
BSAC


While MEMS resonators are about to demonstrate their potential for future transceiver architectures, the need for low-parasitics low-power performances implies shrinkage towards fully integrated systems. The preliminary goal of this project is to provide access to a post-process scheme of SiGe structures that enables integration of GHz resonators with deep-submicron CMOS RF ICs available from a commercial vendor.

Email contact: equevy@eecs


Proximity Electric Power Sensing for Demand Response Mote

Justin Phelps Black, Jonathan Foster, Xin Yang and Vikram Gowrish
(Professor Richard M. White)
BSAC


The overarching goal is to identify technology that will enable domestic electricity users to make more efficient use of electric power. Elements will include inexpensive wireless revenue metering, plus electricity use and thermal/humidity monitoring and control inside houses based on knowledge of present and short-range future weather predictions and electric power costs. The term demand response (DR) refers to the ability of electricity users to respond automatically to time- and location-dependent price and contingency signals to reduce/shift loads.

Email contact: jdf@eecs


Resonant Drive: Sense and High Voltage Electrostatic Drive Using Single MEMS Electrode

Baris Cagdaser
(Professor Bernhard Boser)
BSAC


A new technique for electrostatic drive and sense is developed. The main goal is to simplify the complexity of drive and sense circuitry. The new approach will alleviate the need for high voltage circuitry even in voltage demanding MEMS applications. Since only a single drive capacitor is needed for both drive and sense, resonant drive will also simplify the design of the physical device.

Email contact: cagdaser@eecs


Room-Temperature Synthesis of Carbon Nanotubes

Dane Christensen
(Professor Liwei Lin1)
BSAC


This project's goal is to develop a microelectronics-compatible synthesis method for Carbon Nanotubes and apply it to create novel sensors and transducers.

1Mechanical Engineering

Email contact: lwlin@me


Scanning Probe Methods for the Characterization of Nanomechanical Resonators

Alvaro San Paulo and Xuchun Liu
(Professor Jeffrey Bokor)
BSAC


The goal of this project is the development of atomic force microscopy and laser interferometry methods for the electromechanical characterization of nanomechanical resonators.

Email contact: alvaro@eecs


Selectively Addressed MEMS Digital-Mirror Arrays for Adaptive Optics

Blake Ching Yu Lin
(Professors Richard S. Muller and Tsu-Jae King Liu)
BSAC


This project investigates the design of MEMS-deformable-mirror (DM) arrays for adaptive-optics (AO) systems. In these arrays, micromirror segments are individually addressed and controlled to correct the aberrated wavefronts of an optical beam dynamically. This correction improves image resolution in telescopes or vision-science instruments. Our research focuses on developing a CMOS-compatible MEMS process to integrate micromirrors with their driving electronics and control circuitry. In this way, we will control large mirror arrays selectively.

Email contact: blakelin@eecs


Self-Healing RF MEMS Switch

Rishi Kant
(Professor Roger T. Howe)
BSAC


The objective of this project is to create an RF MEMS switch with the capability of self-healing in order to perform hot switching of large currents. Traditional electrostatic actuation is used for closing the switch. Liquid Gallium is used for making contact thus alleviating the problem of thermal and mechanical deformation due to hot switching. The liquid droplets are confined to a distinctive pattern by exploiting the different wetting affinities that gallium has to different materials. Thermally vaporized gallium is reclaimed during the closing of the switch. The benefits derived from such a design are longer lifetime and higher current handling capacity.

Email contact: rik9@eecs


Sickle-Cell Anemia Event Detection Sensor

Jennifer Wade
(Professors Dorian Liepmann1 and Albert Pisano)
BSAC


The objective of this project is to design, fabricate and test a micro-flow channel that can be used to accurately simulate, detect, analyze, and predict the rheological properties of Sickle Cells flowing through arteriole bifurcations of various diameters and lengths. One property of interest is the effect blood osmolarity variations has on Hb SS red cell compliance, as well as the variation of hematocrit levels. Ultimately, this data and the trends extrapolated from it will be used to understand the differences between healthy and Sickle blood flow in arterioles, as well as provide information that can help elucidate some precursors of vascular occlusion in sickle cell anemic individuals. This research may also have potential applications to other hemoglobinopathies.

1BioEngineering

Email contact: jsw@eecs


Silicon Carbide-based Nanomechanical Filter Arrays

Jingchun Zhang and Carlo Carraro
(Professors Roya Maboudian1 and Roger T. Howe)
BSAC


SiC has a high acoustic velocity and extremely stable physicochemical properties preferable for ultrahigh frequency resonators. The goal of this project is to design, fabricate, and test novel SiC nanomechanical filter arrays for integrated microwatt transceivers. In order to achieve this goal, a series of microfabrication technologies including low-temperature CVD, reactive ion etching, and metalization of poly-SiC films need to be developed. In addition, the mechanical, thermal, and electrical properties of the deposited SiC films need to be characterized. Recent progress includes investigation of the doping effect on the crystal quality of polycrystalline SiC, characterization of carrier concentration and carrier mobility, and contact resistivity characterization of the Ni/SiC system.

1Chemical Engineering

Email contact: jingchun@berkeley.edu


Single-Cell Electroporation Microchip

Michelle Khine, Adrian Lau and Cristian Ionescu-Zanetti
(Professor Luke Lee1)
BSAC


We developed a disposable single cell electroporation device which can be used in a multiplexed format. This chip design demonstrates the effectiveness of using a microfluidic device with individual lateral cell trapping sites to selectively immobilize and locally electroporate single cells in parallel. Single cell electroporation increases the cell membrane's permeability, allowing polar substances otherwise impermeant to the plasma membrane (such as dyes, drugs, DNA, proteins, peptides, and amino acids) to be thus introduced into the cell. Our polydimethylsiloxane (PDMS)-based single cell electroporation chip can focus the electric field, eliminating the need to manipulate electrodes or glass pipettes. Moreover, this disposable device allows parallel single cell electroporation, along with simultaneous electrical and optical measurements. We demonstrate the effectiveness of our device design by electroporating Hela cells using low applied voltages (<1 V). We found that the average transmembrane potential required to electroporate Hela cells is 0.51 V+/- 0.13. Membrane permeation is assessed electrically by measuring characteristic 'jumps' in current that correspond to drops in cell resistance, and microscopically by recording either the escape of cytoplasmic dye Calcein AM or the entrance of Trypan blue stain. We were furthermore able to demonstrate reversible electroporation. This provides an efficient means of introducing otherwise impermeant material, such as drugs, DNA, and protein, into individual living cells.

1BioEngineering

Email contact: ionescu@berkeley.edu


Steered Agile Laser Transmitter (SALT)

Matthew Emanuel Last
(Professor Kristofer Pister)
BSAC


The goal of this project is to develop steered narrow-beam optical communication devices capable of communicating wirelessly between cubic-millimeter autonomous sensing platforms.

Email contact: mattlast@eecs


Stiction in MEMS

Brian Bush
(Professor Roya Maboudian1)
BSAC


Electrostatic forces, due to trapped charge or applied voltage, can lead to unwanted adhesion in MEMS devices. We wish to use various techniques, including Electronic Force Microscopy (EFM) and Cantilever Beam Arrays (CBA), to characterize the effect of surface modifications on the electrical properties of MEMS components and to better understand the forces that cause stiction. This knowledge will enable one to develop novel surface modifications or self-assembling monolayers that are specifically designed to combat stiction due to electronic forces.

1Chemical Engineering

Email contact: bbush@berkeley.edu


Sugar

David Samuel Bindel, David G Garmire, Shyam Kumar Lakshmin, Jason Clark, Corie Cobb, Raffi Kamalian, Tsuyoshi Koyama, Jiawang Nie and Ying Zhang
(Professors Alice Agogino1, Zhaojun Bai2, Sanjay Govindjee3, Kristofer Pister, Carlo H. Séquin and James Demmel)
BSAC


Our goal is to create an efficient system-level analysis tool for the simulation and design of complex MEMS. The program is to be readily accessible, easy to use and extend, and capable of giving speedy results for complex systems, including static, steady-state, transient, sensitivity, and bifurcation analysis results. We will also support higher-level programs for design optimization and synthesis. We will incorporate state-of-the-art numerical libraries, as well as integrating new numerical techniques, such as improved model reduction methods. We will also build software to capture measurements from optical tools, and compare those measurements to simulations. We will make our software freely available as a package accessible from MATLAB and as a web service.

1Mechanical Engineering
2CS
3Civil Engineering

Email contact: sugardesign@bsac.eecs


Time Division Multiplexed Microfluidic Lateral Patch Clamp Array

Mike Mueller, Cristian Ionescu-Zanetti and Niraj Patel
(Professor Luke Lee1)
BSAC


Our goal is to apply newly emerging technology in MEMS and microfluidics to create a high-throughput electrophysiology platform for characterizing ion channels in drug discovery and drug development. We plan to replace the micropipette of the original patch clamp design with Ag/AgCl electrodes, and form arrays of electrodes to create a high-throughput patch clamp system on a chip. The device should be high-throughput, to increase the amount of data able to be collected per unit time. Furthermore, the device should be largely automated, in order to reduce or eliminate the manual labor traditionally associated with the patch clamp technique. At the same time, we would like to maintain high ýgiga-ohmý seals and not sacrifice data quality in our quest to achieve ease of use and implementation.

1BioEngineering

Email contact: ionescu@berkeley.edu


Ultra-Low Power RF CMOS Transceiver Architectures

Ben Walter Cook
(Professor Kristofer Pister)
BSAC


The goal of this project is to make dust-sized, wearable, autonomous wireless sensor nodes practically realizable by substantially reducing the power demands of the systemys most power hungry section; the communications circuits. To that end, a novel RF transceiver topology capable of delivering adequate performance for sensor networks while consuming remarkably little power has been developed. Substantial power reduction in the RF circuits is absolutely necessary to shrink the size of battery required to sustain an autonomous sensor node. The goals for power consumption are dependent on the particular requirements placed on the receiver (i.e., data rate, range, interference level, etc.). The target application here is short range (<30 m) communication at a data rate of 500 kb/s. Assuming -7 dBm transmitter output power and 10 dB SNR required for demodulation, the receiver should have a noise figure (NF) less than 10 dB. Given this spec, the goal for total receive power consumption is 200 µW. Simulated performance of the current design achieve this goal.

Email contact: cookbw@eecs