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, single and multi-objective genetic algorithms, as well as simulated annealing algorithms have been successfully implemented for several design synthesis examples using the SUGAR simulation tool as an engine. The research will be framed within a larger research program for developing general-purpose MEMS synthesis tools.
The goal of this project is to extend the probe technique by combining it with optical excitation to characterize the nanomechanical resonators without electrical drive structures.
1Postdoctoral Researcher
2Graduate Student (non-EECS), UC Davis
The Steered Agile Laser Transceivers (SALT) project focuses on developing a system capable of doing two-way >1 Mb/s laser communication between small airplanes over distances as far as 5 km. Precision beam steering systems are essential for using highly directional lasers in free-space communication. As part of the SALT project, the goal of this research is to design a precision pointing and stabilization system using MEMS devices.
Our project aims to develop and investigate digital post processing methods and circuit techniques that allow efficient, low power implementation of high performance analog-to-digital converters (ADC) in fine line technologies. The research focuses on a continuous background self-calibration technique applied to a high-speed pipeline ADC topology.
The goal of this project is to develop the actuator for a novel integrated digital output z-axis gyroscope with frequency-locked resonance.
The goal of this project is to develop a system for the measurement of strain in automobile roller bearings achieving a resolution of .1 microstrain (me) over a range of ± 1000 me and a bandwidth of 10 kHz.
The goal of this project 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.
1Undergraduate (EECS)
The goal of this project is to develop a high-order sigma-delta sense interface for micromachined gyroscope sensors. The main priorities are providing sufficient stability margin and low power consumption while maintaining the intrinsically high resolution of the sensor element.
The MEMS rotary engine power system (MEMS REPS) 2.4 mm engine is the power generating source for the MEMS REPS and it will be the first design to be integrated with an electric generator.
The goal of the Mini Rotary Engine Power System (Mini 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.
The goal of this project is to design, fabricate, and characterize an electrochemical oxygen micro-generator suitable for use in high density miniature cell culture arrays. As the design and fabrication of the bubbler are complete, we are currently characterizing the gas production of the bubbler. Current goals include the characterization of growth rates of bacterial suspensions growing on oxygen supplied by our bubbler and the determination of generated gas purity.
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 techniques including deposition, etching, and metalization of poly-SiC films will be developed. In addition, the mechanical and electrical properties of the deposited SiC films will be characterized.
The goal of this project is to design, fabricate, and test multi-pole nano-mechanical resonators (NMRs) with center frequencies in the GHz range for low-power telecommunications applications. We intend to utilize polycrystalline silicon-germanium (poly-SiGe) and poly-Ge as the structural and sacrificial layers that will allow us to fabricate MEMS directly on top of foundry CMOS.
The goal of this project is to optimize the SiGe film deposition process with laser thermo annealing and make 3 mm SiGe film possible for post CMOS radio frequency MEMS resonators. Economical growth rate, low thermal budget, small stress gradient, and high quality factor are the requirements for the SiGe film. Reducing capacitance feedthrough and expanding the frequency limit of the electronics will be essential in high frequency signal detection.
The goal of this project is to extend the fluidic self-assembly processes demonstrated recently at BSAC in order to assemble microfluidic components onto plastic substrates.
The goal of this project is to take the fluidic microassembly technique, developed by Uthara Srinivasan, and extend it such that electrical interconnects can be made between a microcomponent and the substrate.
The purpose of this work is to evaluate the performance of two different frame gyroscopes, namely the inside drive outside sense (IDOS) and the inside sense outside drive (ISOD) frame gyroscopes. To verify the performance difference, these integrated surface-micromachined frame gyroscopes were designed and fabricated on a single chip with the analog devices modular-MEMS (MOD-MEMS) process using 6 mm thick polysilicon as the structural material and a 5 V 0.8 mm foundry process.
The goal of this project is to develop and batch fabricate a very precise electrode for a high performance capacitive sensor using microfabrication techniques.
The goal of this research is to design and fabricate a millimeter-wave patch antenna, an anchor-tolerant ring resonator, and integrate the antenna and resonator to demonstrate the receiver front-end of an integrated radio platform.
The goal of this research is to design an X-axis rate gyroscope with vertical drive, to enable in-plane sensing.
The goal of this project is to understand the forces on cells in microfluidic devices with certain geometries and precisely controlled forces in order to manipulate cells for biotechnology applications. This includes cell lysis for mTAS applications and poration for gene and large molecule delivery.
1Undergraduate (EECS)
The goal of this research is to make an ultra sensitive label-free DNA microarray by employing the nanogap dielectric junctions.
The goal of this research is to study various aspects of nanogap junctions and finally to make ultrasensitive biosensors using the nanogap junction.
The goal of this project is to integrate and qualify micro-optical systems with microfludic channels in order to advance the functions of micro total analytical systems (mTAS). The integrated microfluidic optical systems (iMOS) with planar optical systems have the potential to open a new period to mTAS because of low-cost, simple fabrication steps and aberration-free optical systems. We believe the iMOS provide a new paradigm of integrating optical systems to mTAS.
The XZR comb drive with electrostatic and thermal actuation will provide multi-DOF controllability and high frequency operation, and is an ideal candidate for optical MEMS applications. The simplicity of fabrication will provide an economical and robust process. The XZR multi-DOF comb drive-based micro-optical components will be tested for fast image scanning, optical tuning facility, and beam steering as well as high-resolution optical detection capability.
In this project, nanostructures will be batch fabricated and tested for their ability to enhance biological Raman signal in surface enhanced Raman spectroscopy. Ultimately, these structures will be integrated into an arrayed microfluidic network environment for dynamic and multiplexed identification and detection of trace amounts of biomolecule.
The goal of this project is to develop polymer-based actuators that can operate inside microfluidic systems and investigate their capabilities and limitations.
This project aims to develop a filtration system that can: (1) perform multi-stage bandpass filtration; (2) develop independent flow control at different filtration stages; and (3) be easily adapted to various BioMEMS layouts as a part of the sample preparation process for mTAS applications.
The goal of this project is to build a micro biosensor system for monitoring ions around a single cell, for example Na+, K+, Ca2+, H+, which can be used to monitor the single cell character.
The goal of this project is to implement a MEMS confocal microscope based lab-on-a-chip system for single molecular detection using both silicon and polymer MEMS technology. Major challenges include the realization of a confocal imaging scheme to within a cubic millimeter in size and array type integration of the microscopes on top of the microfluidic network.
The goal of this research project is the investigation of the electronic properties of DNA by capturing and straightening DNA at nano-gap electrodes and the feasibility of DNA junction diodes.
The focus of this research project is the optimization of the tissue-to-device interface using nanopillars to reduce impedance and enhance biocompatibility and selectivity.
The focus of this research project is the development of a prefilled MEMS syringe for painless injection of a suspension of fine drug powder and biocompatible liquid through an array of hollow microneedles into the epidermis under the stratum corneum.
In this project, using solely capillary forces to flow, microscale fluid flow behavior will be characterized with respect to surface properties of the substrate, fluid properties, and the geometries of the microfluidic systems.
The goal of this project is the development of a disposable continuous in-vitro minimal invasive micro glucose monitor.
The focus of this project is harnessing selection-based cell adhesions to perform cell separation in microstructured fluidic channels. Cell separation refers to the capture and concentration of cells and even to fractionating different cell types from a continuously flowing sample in a manner suited to the requirements of micro-assay systems.
The main goal of this project is the development of water-powered, osmotic micropumps to serve as clean, compact, and inexpensive power sources for bioassay and drug delivery applications. Osmosis is applied to design micropumps fabricated by MEMS-compatible processes for the integration with other microfluidic devices. The innovative osmotic micropumps will be able to serve as clean, compact, and inexpensive power sources for bioassay and drug delivery systems.
The overall group project aims to produce a high-resolution MEMS strain gauge for applications on steel. This particular project will develop a rapid bonding process for installing vacuum sealed MEMS strain sensor modules to steel components. To ensure that the MEMS strain gauge accurately measures the strain within a steel substrate, properties of the bond layer between silicon and steel must be observed and determined. A uniaxial strain rig will be used to measure the Youngs modulus, creep, and hysteresis of silicon-steel bonds within a temperature controlled environment. A mN strain gauge will be used to characterize the shear modulus and strength of microfabricated bonds of various shapes and widths.
The goal of this project is to develop wafer bonding and hermetic sealing technology based on induction heating for MEMS and IC post packaging. We will use induction heating to remotely operate thermal actuators for the MEMS assembly.
The goal of this project is to model, design, fabricate, and test a micro force and motion sensor to identify the severity of the disk/head interfacial contact and the effect on the data accessing during the hard disk glide test.
The goal of this project is to develop ultrasonic bonding as a new bonding method for MEMS level hermetic sealing and packaging. We aim to demonstrate the feasibility and find the right bonding conditions and parameter values.
The goal of this project is to develop and characterize a high frequency MEMS resonator for wireless communication applications with CMOS compatibility.
1Postdoctoral Researcher
The goal of this project is to develop microbatteries that can be integrated with disposable MEMS devices as power sources for BioMEMS and MEMS products, including disposable diagnostic and BioMEMS chips.
1Postdoctoral Researcher
The goal of this project is to develop both silicon and polymeric chemical sensors to be integrated with micro-osmotic pumps, ultra low leakage micro-valves, micro-accumulators, and dialysis needles, for complete a bioassay system.
The focus of this project is to develop a nickel-composite film via a low temperature process that has superior mechanical and electrical properties for applications in RF MEMS.
This project specifically aims to develop a micromachined microbial fuel cell (mMFC) as a bio-compatible power source for implantable medical devices. In general, however, mMFCs are also being developed as alternatives to other micro power sources like micro batteries and micro engines.
Integrated manufacturing of nano-to-micro systems is critical for the practical applications of nanotechnology. This research project aims (1) to develop an integrated manufacturing process to connect a nano-system to a micro-system and (2) to utilize the integrated structure for practical applications (such as enhanced sensors or heat dissipation).
The goal of this project is to develop microencapsulation processes for fluids with potential applications to pharmaceutical, chemical, and optical MEMS devices.
The main goal of this project is the development of water-powered, osmotic micropumps for bioassay and drug delivery applications. Osmosis is applied to design micropumps fabricated by MEMS-compatible processes for the integration with other microfluidic devices. The innovative osmotic micropumps will be able to serve as clean, compact, and inexpensive power sources for bioassay and drug delivery systems.
The goal of this project is to develop a facile method for the realization of SiC-coated Si and SiC-based components for MEMS-based micropower systems.
The goal of this project is to fabricate 3D refractive microlenses and lenslets using surface micromachining and to investigate their use in micro-optical systems.
This project will demonstrate piston and tip/tilt actuation of an array of 500-750 µm-radius hexagonal mirrors with fill factors exceeding 98%. The mirrors will actuate above the substrate in a piston motion over a range of greater than 5 µm for astronomy applications and over 20 µm for vision science applications. Tip/tilt rotations of about a degree are also required. The frequency response must exceed 4 kHz for astronomy and 100 Hz for vision science. Finally, a scalable interconnect must be investigated that will connect from hundreds to thousands of mirrors.
1Postdoctoral Researcher
The focus of this project is to fabricate highly sensitive electrostatic-charge and remote-voltage sensors, using silicon micromachining.
I am working in support of a large project to design a MEMS strain sensor for placement on steel. The goal of the design is to measure small strain in the substrate over a wide range of operating temperatures using a small gauge length. The long-range goals for my portion of the project are to thoroughly describe and predict the changes in the natural frequencies of various novel resonator and chip designs for a range of substrate displacements and operating temperatures.
A fuel injection for the MEMS rotary engine power system (REPS) is being designed, fabricated, and characterized with the long-range goal of incorporating this system as the engine’s intake manifold. To attain this goal it is essential to gain an understanding of evaporation, namely the phase eruption phenomena, of liquid hydrocarbon fuels in microchannels.
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.
The goal of this project is to design a dynamic fuel evaporator for a MEMS rotary engine power system (REPS). The instability of microscale flow boiling in microstructures will be identified to synchronize with the engine’s working frequency so as to generate a constant mass-flow rate of vaporized fuel.
1Postdoctoral Researcher
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 will have a continuous power output of ~100 mW, and is designed to leverage the specific energy advantage of liquid hydrocarbon fuels over current portable power sources. The design also allows for rapid field implementation in a variety of applications requiring localized power generation. Applications include interconnected sensor networks or land warrior power supplies.
The objective of this research project is electroplating a soft magnetic material into the silicon rotor for the integrated generator design of the MEMS REPS project. We will use characterization of an advanced electroplating cell to control the deposition rate, composition, and residual stress of nickel-iron (NiFe). We will use fluidic self-assembly to position pre-released rotors over a partially insulated seed layer for selective deposition.
The goal of the MEMS REPS/apex seal design is to model, design, and fabricate an engine sealing system capable of high compression ratios.
The focus of this project is to design and fabricate a mechanical interconnect system for use in MEMS and miniaturized applications, enabling modular construction of complex 3D structures, and generic enough to be compatible with most designs without modifying the original devices.
The goal of this project is to design isolation trenches on a MEMS strain gauge such that the sensors accurately measure the strain field on a steel substrate, and devise methods to protect CMOS from strain experienced by the remainder of the strain gauge package.
For the demonstration unit of the 2.4 mm Wankel rotary engine, the engine will be redesigned as an expander to be run on compressed gases. Once the expander micro-fabrication is complete, an integrated generator will be incorporated to power an electronic device.
The focus of this project is to design a valve suitable for integration into a portable, wearable microfluidic device. Wearable microfluidic devices have a very limited supply of working fluid and the use of this fluid must be very tightly budgeted to increase the life of the system. Microvalves incorporated into this system must have incredibly low leakage rates to reduce wasted fluid by increasing the precision that fluid is distributed to other parts of the system. Additionally, due to the meager amount of energy available from the system battery, the valves must have very low power consumption.
The goal of this project is to complete the fluidic modeling and determine the leakage rates of a micro-wankel engine. We will then aim to verify the modeling through experimental findings.
The focus of this project is to fabricate a strain sensor capable of measuring micro-strain (10-6) with a gauge length no greater than 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.
The development of a portable power system using liquid hydrocarbon as fuel promises significant advantages in energy density over conventional batteries. The goal of MEMS rotary engine power system (REPS) is to fabricate a small scale (1.2 mm3 displacement) rotary (Wankel) engine with an integrated electric generator and all necessary ancillary equipment (thermal management, fuel delivery, thermal packaging, etc.).
1Postdoctoral Researcher
In this project, we will fabricate, test, and analyze double-T fluid channels. The results will determine the feasibility of using pressure driven flow through a double-T metering section for discrete volume definition.
This research is based upon the hypothesis that there is a relationship between devitrification temperature and the microstructure of Ni-Ti films that are initially deposited in an amorphous state and then subsequently annealed to induce crystallization. This is a fully testable hypothesis, amenable to parametric control of annealing temperatures, annealing times, dynamic observations, and high spatial resolution characterization of the crystallized product.
1Postdoctoral Researcher
The overall group project aims to produce a high-resolution MEMS strain gauge for applications on steel. This project aims to design and fabricate test rigs. The test rig design has three objectives: quantify accuracy and resolution of the MEMS strain gauges attached to steel bodies, provide comparison performance data to conventional foil strain gauges, and verify that these MEMS strain gauges will be able to accurately measure narrow-width strain events. A four-point bend test rig has been produced to satisfy the first two project aims. Further work will consist of testing specimens and integrating temperature control into the test rig.
In this project, nano-scale resonators will be designed and fabricated to mechanically modulate a magnetic field, and incorporated into an integrated nano mechanically-regulated atomic clock in order to reduce size and power consumption. The project responsibility is transitioning from Ms. Robin Liu to Mr. James Porter.
The goal of this project is to provide a research infrastructure of networked sensors for the College of Engineering at UC Berkeley. The infrastructure is intended to survive for a year on the energy from a pair of AA batteries per sensor node. It will support multiple applications simultaneously and allow public data retrieval from the Internet.
The goal of this project is to develop an ultra-low energy integrated circuit that will form the core of a self-contained, millimeter scale sensing and communication platform for a massively distributed sensor network. The integrated circuit will contain an integrated sensor, an A/D converter, microprocessor, SRAM, communications circuits, and power control circuits. The IC, together with the sensors, will operate from a power source integrated with the platform.
In this project, a CMOS imaging receiver will be designed to receive low-power, free-space optical transmissions between unmanned aircraft, or other small, low power platforms, at a distance of several kilometers.
The goal of this project is to guide the development of sensor network theory. In this nascent field, it is important to intelligently design experiments that explore the capabilities and discover the limitations of data collection from sensor networks. We seek to design quantifiable measures of algorithmic performance, apposite terminology, and paradigmatic perspectives to aid in the development of an information theory.
The goal of this project is to develop steered narrow-beam optical communication devices capable of communicating wirelessly from a cubic-millimeter autonomous sensing platform.
The goal of the Cots-Bots project is to use commercial off-the-shelf (COTS) components to build and deploy inexpensive and modular robots, which can be used to investigate algorithms and cooperation in large (>50) robot networks. Distributed robot networks have applications ranging from mapping and exploration to constructing complex systems. Work in BSAC is targeted toward providing a standard robot platform with a variety of modular sensor and actuator boards to test algorithms to solve these problems. Many of the algorithms demonstrated on the cots-bots platform will find future use in the Microrobot project.
The focus of this project is to create a class of articulated autonomous microrobots with a volume of less than 1 cm3.
The goal of the MEMS rotary engine power system (REPS) integrated generator project is to design and fabricate a millimeter-scale electric machine capable of converting the mechanical torque of a liquid hydrocarbon fueled MEMS rotary engine into electrical power.
The goal of this project is a low cost device that is able to size and count air particulates with sizes under PM 2.5 and retain the particulates for subsequent composition analysis. 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 particulate spatial and temporal maps. We will explore integration with pollutant sensors such as that for NOx and SO2. We aim to extend the applications of a micro corona discharge device to a micro ozone generator for biological sterilizing units, non-mechanical micro air pumps, and ESD control.
1Graduate Student (non-EECS), UC Davis
2Postdoctoral Researcher
The objective of this project is to develop micro-electromechanical tunable capacitors employing dielectric fluids. In the case of electrostatic, mechanically tunable capacitors, the goal is to increase the capacitance per unit area and the tuning range, reduce the mechanical noise, and improve long-term reliability.
1Graduate Student (non-EECS)
2Postdoctoral Researcher
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.
1Graduate Student (non-EECS), UC Davis
This project seeks to integrate MEMS and planar lightwave circuits (PLC) to create novel monolithic systems for telecommunication. Specific devices are under design and their functionality will be incrementally verified while fabrication and integration technologies are being developed.
1Graduate Student (non-EECS), UC Davis
A novel micromachined biomimetic device: the directional diaphragm for acoustic transducers, has been designed, modeled, simulated, fabricated, and tested. We have fabricated a directional microphone by employing the biomimetic directional diaphragm.
1Graduate Student (non-EECS), UC Davis
The goal of this project is to develop tunable inductors and transformers that have high Q-factors and high tuning ratio for wireless communication applications.
1Graduate Student (non-EECS), UC Davis
2Postdoctoral Researcher
The goal of this project is to develop a smart universal game board which can be reconfigured to play any board game using MEMS technology.
1Graduate Student (non-EECS), UC Davis
We intend to develop a 4-bit variable inductor array using lateral-contact microrelays to provide a wide tuning range and design flexibility for building blocks using passive RF MEMS components in wireless communication systems.
1Graduate Student (non-EECS), UC Davis
We seek to develop a new type of microactuator based on high aspect ratio piezoelectric processing. These microactuators utilize a combination of high aspect ratio patterning and conformal deposition in their fabrication. The output motion of these actuators is directed laterally, that is, in the plane of the wafer, allowing the interaction of actuators with each other. Modeling of these actuators indicates that they should provide large displacements and forces due to the high energy density of the actuator structure.
Sequential flow injection (FI) involves the temporary immobilization of functionalized microspheres as a renewable surface for (bio) chemical assays. We describe a microfabricated FI system that employs the ultrasonic flexural plate wave (FPW) device to acoustically capture microspheres from fluid flow.
We report on the feasibility of coupling electrochemical vapor sensors to the Smart Dust wireless communication platform. Small, sensitive, and selective electrochemical sensors, which are available commercially for many chemical vapors, can advantageously be coupled to the Mica motes in a Smart Dust network.