Research Project Descriptions
A complete copy of the project descriptions (Including: Approach and Methodology, Results and Accomplishments and Milestone Dates) are available to Center Members in the Members Only section of our website at www.wimserc.org
Contents:
Micropower Circuits Micropackaging, Microfabrication, and Power Source Technologies Environmental Sensors & Subsystems Biomedical Sensors & Subsystems Wireless Interfaces
Micropower Circuits
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Title:  Improved Process Variation Detection and Compensation for Gen3 WIMS Microcontroller
Graduate Students: Amlan Ghosh (ECE-UT) Funding Source: WIMS ERC and IBM	Faculty Advisor: Richard B Brown (ECE-UT) Work Began: 09/20/2007
Project Goals:
The need for accurate detection schemes to facilitate the mitigation of process variations has increased in the nm technology era. A new detection technique will be incorporated in the Gen3 WIMS microcontroller that uses slew, as well as delay, to determine n- and p-type transistor parameters. The transistor thresholds can be adjusted using the process variation data to drive the substrate bias. When circuits are compensated for process variation in this way, they will operate optimally with the minimum supply voltage for a given frequency, thereby reducing power dissipation.
Title:  Subliminal: An Ultra-Low-Energy Sensor Network Processor
Graduate Students: Scott M. Hanson (EECS), Bo Zhai (EECS) Funding Source: WIMS ERC Other Investigators: David Blaauw (EECS)	Faculty Advisor: Dennis M Sylvester (EECS) Work Began: 01/01/2005
Project Goals:
The project goal is to investigate new architectures and circuit structures for applications requiring battery lives on the order of months and years. In particular, our work focuses on the wireless sensor network application space. Within this space, cost and energy reduction are the primary goals, while performance is a secondary concern.
Title:  A Universal Microsensor Interface Circuit for Low-Power Microsystems
Graduate Students: Chao Yang (ECE-MSU) Funding Source: WIMS ERC	Faculty Advisor: Andrew J Mason (ECE-MSU) Work Began: 05/15/2002
Project Goals:
In ultra-miniature and low-power multi-sensor microsystems, the interface circuitry (signal conditioning and processing) plays an important role in achieving high performance and hence has been identified as a key component in the whole system. This project seeks to develop a full-featured, low-power, single-chip, hardware interface that interrogates a wide range of MEMS and biochemical sensors or actuators. In the first phase of this effort, the Universal Micro-Sensor Interface (UMSI) chip was developed. In the second phase of the project, low-power circuitry to implement on-chip impedance spectroscopy is being developed. This new interface will add significant functionality to the UMSI chip and support readout of a wide range of nanomaterials and biosensor arrays.
Title:  Low Power and Robust Digital Circuit Design
Funding Source: WIMS ERC	Work Began: 01/01/2003
Title:  Design and Optimization of Power Supplies for Wireless Integrated MicroSystems
Graduate Students: Fabio Albano (MSE) Funding Source: WIMS ERC	Faculty Advisor: Ann Marie Sastry (ME) Work Began: 01/01/2001
Project Goals:
Accurate modeling of power supply requirements demands detailed information about expected system losses and comparison with available energy and power densities in power supplies. This project seeks to develop power supply requirements based on models of devices and fabrication of special-use battery systems for: 1) the cochlear/neural prosthesis testbed and 2) the intraocular testbed.
Title:  Micropower Digital SOI
Graduate Students: Robert M. Senger (EECS) Funding Source: WIMS ERC Other Investigators: Scott A. Mahlke (EECS)	Faculty Advisor: Richard B Brown (ECE-UT) Work Began: 01/01/2001
Project Goals:
Power consumption of digital circuits has moved to the forefront as one of the most significant problems facing system designers. This problem can be subdivided into two key issues: power supply limitations and heat dissipation. As electronic devices become more portable, circuit designers must employ low-power techniques to achieve acceptable battery lifetimes and reduce cooling costs. This project seeks to alleviate these problems by exploring low-power digital circuit design from several different angles. First, architectural and processing techniques will be analyzed from the power perspective. Second, low-power compiler and synthesis techniques will be explored in the context of the WIMS chip. Third, low-power circuit design techniques will be investigated in IBM’s advanced 65nm partially depleted SOI process. We expect this multi-faceted approach will result in ultra-low-power microcontroller design techniques that advance the state-of-the-art in mixed-signal system design.
Title:  A Low-Power DSP Architecture for a Cochlear Implant System-on-a-Chip
Graduate Students: Eric Marsman (EECS) Funding Source: WIMS ERC	Faculty Advisor: Richard B Brown (ECE-UT) Work Began: 09/01/2003
Project Goals:
This project has developed and implemented a digital core that executes the continuous interleaved sampling (CIS) algorithm for a CI. Figure 1 shows a schematic diagram of the CIS algorithm. This core was instituted as part of the WIMS MCU and built as part of the cochlear prosthesis testbed. This architecture has several programmable features in order to achieve the same variability for patient specific parameters as present-day commercial implants. However, designing a custom architecture tuned specifically for this sound processing algorithm is a lower power implementation than using a software-programmable DSP chip as part of the system.
Title:  Low-Energy Capacitance to Digital Converter for Intraocular Pressure Sensor
Graduate Students: Yu-Shiang Lin (EECS) Funding Source: WIMS ERC Other Investigators: David Blaauw (EECS)	Faculty Advisor: Dennis M Sylvester (EECS) Work Began: 09/01/2005
Project Goals:
This project is part of the intraocular pressure project that consists of a pressure sensor, capacitance-to-digital converter (CDC), microprocessor and battery. The goal is to have an integrated system that is able to be implanted in the eye. It is designed to be capable of measuring eye pressure continuously and record the results in SRAM. Two major constraints for the circuit are area and power. Since it has to be small enough for implantation purposes, the ideal dimension would be under 500μm by 500μm. Also, due to the small form factor for the battery, the lifetime is limited. In order to support an operating time of six months to one year, the average power consumption is targeted at 5nW. In this application, there is nearly no speed concern, so that an appealing option is to trade speed for more power headroom. With its quadratic dependence on power consumption, decreasing Vdd is very effective in cutting down dynamic power. Therefore, the circuit has to be operated in subthreshold region to meet the power requirement. Traditionally, CDCs have been implemented with complicated analog circuits that are hard to fit into our power budget. The proposed CDC structures are all digital designs and thus more suitable for subthreshold operating voltages. Several designs will be discussed and compared in the next sections.
Title:  Integrating Software and Hardware Components for Both NPT and EMT Testbeds
Graduate Students: Daniel E. Mera (ECE-UPRM) Undergraduate Students: Angel J. Rios (ECE-UPRM), Felix J. Cedeno (ECE-UPRM), Misael Perez (ECE-UPRM), Luis D. Lahoz (ECE-UPRM), Roberto Santos (ECE-UPRM), Rafael E. Bey (ECE-UPRM), Jonathan Torres (ECE-UPRM) Funding Source: WIMS ERC	Faculty Advisor: Nayda G. Santiago (ECE-UPRM) Work Began: 09/01/2007
Project Goals:
The main goal for our project is to demonstrate the functionality of a code for both Cochlear Implants and Micro Gas Chromatograph testbeds. Both testbeds are composed of components and subsystems created by different groups at the WIMS ERC. Integrating some of the components imply the development of code at different levels, but mostly at the embedded system level. For the Cochlear Implant testbed, this code has already been tested on a commercial platform; however, porting it to the actual system is our current goal. For the micro Gas Chromatograph testbed, our goal is to develop preprocessing and controlling code that will allow the system to interact with pattern recognition code. Our main challenge is integrating everything into a working prototype.
Title:  An Integrated Microsystem for Environmental Sensing Powered by Energy Scavenging
Undergraduate Students: Damon J. Holman (EE-PVAM) Funding Source: WIMS ERC	Faculty Advisor: Pamela Holland Obiomon (EE-PVAMU) Work Began: 09/01/2004
Project Goals:
The goal of this project is to demonstrate a very-low-power microsystem which gathers data from the environment and stores it. The microsystem provides the functions of sensing, data readout, and local storage. This research will focus mainly on the data readout function. The two main architectures used for capacitive sensor readout include either an oscillator and an integrator. Each architecture has limits and trade-offs. The choice of architecture is dependent on application. This project seeks to define the limits and trade-offs between the two sensor readout architectures in terms of accuracy, size, speed, and power.
Title:  Energy Scavenging From Transpiration
Graduate Students: Ruba T. Borno (EECS) Undergraduate Students: Joseph D. Steinmeyer (EECS) Funding Source: National Science Foundation and Intel Ph.D. Fellowship	Faculty Advisor: Michel Martin Maharbiz (EECS) Work Began: 08/02/2006
Project Goals:
We present the first microfabricated system that can scavenge energy from room temperature evaporation to produce electrical power.
Title:  Multimode Energy Scavenging From the Environment
Graduate Students: Tzeno V. Galchev (EECS) Funding Source: WIMS ERC Post Doc: Hanseup S. Kim (EECS)	Faculty Advisor: Khalil Najafi (EECS) Work Began: 05/01/2005
Project Goals:
Self-powered remote microsystems and sensor networks are needed in many emerging applications such as environmental monitoring. The required power for these systems can be generated mainly in two ways: 1) by using electrochemical batteries and microfuel cells and 2) by energy scavenging from environmental sources such as ambient heat, light, and vibration. Although electrochemical batteries and microfuel cells can provide more power, they are not desirable for some applications due to their limited lifetime, and size. A battery large enough to last the lifetime of the sensor would dominate the overall system size, and hence is not very attractive. As the sensor network increases in number and the device size decreases, the replacement of depleted batteries and fuel cells is not practical. Energy scavenging has become popular recently, because of the need for clean power generation process and long lifetime. By scavenging energy, power can be generated from various environmental sources such as ambient heat, light, acoustic noise, vibration, and ambient RF signals. The ultimate goal of this project is to develop a MEMS-based, multimode, micropower generator that can harvest energy from different sources including heat, solar energy, and vibration. Such a generator can generate power with high efficiency regardless of the changes in environmental factors.
Title:  Chip-to-Chip Proximity Communication
Graduate Students: Yu-Shiang Lin (EECS) Funding Source: WIMS ERC Other Investigators: David Blaauw (EECS)	Faculty Advisor: Dennis M Sylvester (EECS) Work Began: 07/01/2005
Project Goals:
In this work, we propose a capacitive coupling-based method where the communication module is fully integrated with the sensor node, on a sub-mm scale. The goal is to allow a passive sensor chip (SC) to be dropped face-to-face onto a data retrieval chip (DR) for read-out without precise positioning. In our system, DR sends power to the SC so that the latter consumes no power during read-out. At the same, time a digital alignment circuit is proposed to overcome misalignment issues when power/signal are sent simultaneously.
Title:  Low Power Digital Circuit Design
Funding Source: WIMS ERC	Work Began: 01/01/2003
Project Goals:
The rapid scaling of process technologies has led to greatly improved performance at the cost of increased power consumption, most prominently leakage power. The sub-threshold conduction current increases by 3-5X in each technology generation due to scaling of the threshold voltage (VTH) while the gate tunneling current increases by 2.5X for every 1 Å decrease in oxide thickness, resulting in a nearly 30X increase in gate tunneling current per technology generation. Such large increases in leakage current have resulted in leakage power estimates of more than 40% of the total power budget for designs in the 90nm generation and beyond. New techniques will be developed to combat this leakage power.
Title:  Design and Implementation of a Third-Generation Microcontroller
Graduate Students: Spencer S. Kellis (ECE-UT), Nathaniel C. Gaskin (ECE-UT) Funding Source: WIMS ERC	Faculty Advisor: Richard B Brown (ECE-UT) Work Began: 09/01/2005
Project Goals:
A third-generation microcontroller is being designed as a control element for a neural prosthesis to operate on an extremely limited power budget. We introduce a block load/store (hereafter referred to as DMA) instruction and experiment with dynamic voltage, frequency scaling, and body biasing as significant methods for reducing power. We also experiment with other core architectural modifications which can improve handling of data flow from an analog processing block. A wireless block will provide UWB communication for low-power, high-bandwidth communication both as a neural prosthesis and in testing and sensor networks. The project will include a test run to adapt new tools and digital libraries to our design environment in preparation for a final tapeout. All design work will be accomplished in IBM 65nm process technology.
Title:  Design and Implementation of Low-Power DMA Architecture for a Cochlear Implant System-on-a-Chip
Graduate Students: Nathaniel C. Gaskin (ECE-UT), Spencer S. Kellis (ECE-UT), Amlan Ghosh (ECE-UT) Funding Source: WIMS ERC	Faculty Advisor: Richard B Brown (ECE-UT) Work Began: 09/01/2005
Project Goals:
Our primary objective is to implement direct memory access (DMA) in the WIMS microcontroller to enhance data transfer between memory and the loop cache. Dedicated DMA instructions are needed to fill the loop cache quickly without incurring the overhead of multiple load-store instructions. These instructions will allow a compiler-managed dynamic loop-cache filling algorithm to control fast, low-power transfer of an entire register window upon branches to or from subroutines and interrupt handlers. Overall power requirements can thereby be reduced, further enhancing the performance and longevity of the microcontroller. In addition to DMA, a low-power standard cell library will be designed and synthesized for several power-hungry blocks of the microcontroller in order to further decrease power requirements during heavy computation in the DSP core. Clock gating will be used to reduce the leakage current during no-operation of a block (power save mode).
Title:  Nanosim Power Analysis of the WIMS Microcontroller
Graduate Students: Spencer S. Kellis (ECE-UT) Funding Source: ERC/IBM	Faculty Advisor: Richard B Brown (ECE-UT) Work Began: 10/01/2005
Project Goals:
The goal of this project is to adapt existing hardware methodologies to create an accurate energy-per-instruction (EPI) model enabling more accurate simulations of EPI within Nanosim. A robust power model of the WIMS microcontroller (MCU) will be created by correlating the results of these simulations with hardware measurements.
Title:  TEST
Funding Source: WIMS ERC	Work Began: 03/23/2005
Title:  System Integration for the Cochlear Prosthesis Testbed
Graduate Students: Nathaniel C. Gaskin (ECE-UT), Spencer S. Kellis (ECE-UT) Funding Source: WIMS ERC	Faculty Advisor: Richard B Brown (ECE-UT) Work Began: 12/18/2005
Project Goals:
Integrate the WIMS microcontroller, the Hybrid Cochlear ASIC, and the telemetry chip to create a low-power implantable system for cochlear prosthesis applications. Build a system on which to run the tone and current-shaping demonstrations to showcase the electrical functionality of the microsystem.
Title:  MEMS-Based Energy Harvesting for Low-Frequency Vibrations
Graduate Students: Edwar Romero (MEEM-MTU) Funding Source: WIMS ERC Other Investigators: Khalil Najafi (EECS)	Faculty Advisor: Robert O Warrington (CoE-MTU) Work Began: 05/01/2006
Project Goals:
Power generation for remote-controlled microsystems has faced limitations due to its energy source. Batteries typically have been used for powering these devices. The applicability of these remote-controlled microsystems has been limited by the battery lifetime and battery size. A trade-off of these two parameters has governed the size, useful life, and capabilities of a system. Batteries are not the best option for applications where chemical reactions are involved, or access to the device is severely limited. Thus, energy scavenging from environmental sources can be an alternative. Energy harvesting has become important recently, because of the almost infinite lifetime and the non-dependency on fuels for clean energy generation. By scavenging energy from sources such as light and vibration, power can be generated. Power generation through light sources can yield a high output, although it is not always a practical choice. In some cases, energy generation from vibration becomes feasible because of the abundant oscillations of the surrounding environment. This vibration frequency is typically below 10Hz. For example, human movements peak at around 1Hz. Thus, harvesting these low-frequency vibrations can generate energy for environmental, wearable, or implantable systems. The focus of this project is on generating energy efficiently from low-frequency vibration. In particular, MEMS-scale energy generators will be explored. A demonstration model will be built and optimized to illustrate how energy can be generated using low-frequency vibrations.
Title:  Ultra-Wide Band RF Front-End for Gen3 WIMS Microcontroller
Graduate Students: Ondrej Novak (EE-UT), Wei Wu (ECE-UT) Funding Source: University of Utah Seed Grant	Faculty Advisor: Cameron T. Charles (ECE-UT) Work Began: 11/01/2007
Project Goals:
The primary objective of this project is to design and implement an Ultra-Wide Band (UWB) RF transceiver that provides a wireless interface between the sensor probes and Gen3 WIMS microcontroller unit. The target application for this transceiver is use with an array of neural probes (such as shown in Figure 1) that require high-data-rate communication in the order of 5-10Mb/s with very-low-power consumption. This system-on-a-chip approach with RF and mixed-signal systems on the same die will reduce the power dissipation of the system. It also offers advantages in size and weight, which provide the most important attributes of any portable device. This single-chip, mixed-signal solution provides benefits of low-power consumption by decreasing the amount of required buffers to drive off-chip loads, including pads and bonding wires, and printed circuit board traces.
Title:  The Phoenix Processor: A 30pW Platform for Sensing Applications
Graduate Students: Mingoo Seok (EECS), Scott M. Hanson (EECS) Funding Source: WIMS ERC Other Investigators: David Blaauw (EECS)	Faculty Advisor: Dennis M Sylvester (EECS) Work Began: 08/01/2006
Project Goals:
To meet the growing demand for pervasive computing systems, we have designed an ultra-low-power integrated platform for sensor applications, called the Phoenix Processor. Recent work has explored aggressive Vdd scaling for reducing active energy. However, the power consumed during idle periods, which can be >99% of the lifetime, dominates total power consumption. To limit sleep-mode power, Phoenix leverages a comprehensive sleep strategy using a unique power-gating approach, a CPU with compact instruction set, a custom low-leakage memory cell, adaptive leakage management in the data memory, and data memory compression.
Title:  Asynchronous ADC
	Work Began: 05/01/2005
Project Goals:
Reducing the power consumption and chip area of ADCs is a big challenge in today’s research since analog-to-digital converters are key building blocks in all communication, sensing and imaging systems. We are investigating a new asynchronous ADC scheme which helps us in this goal by putting most of the accuracy burden on digital circuits significantly improving energy efficiency and size.
Title:  A Micro Thermoelectric Generator for Microsystems
Graduate Students: Niloufar Ghafouri (EECS) Funding Source: DARPA Post Doc: Hanseup S. Kim (EECS)	Faculty Advisor: Khalil Najafi (EECS) Work Began: 06/01/2007
Project Goals:
The rapid growth of portable and low-power electronic systems has increasingly demanded the search for power harvesting methods to replace conventional electrochemical batteries to achieve longer lifetime, smaller volume, and better portability. One potential approach is on-site energy scavenging from various environmental sources such as ambient heat, solar energy and vibration. In this project, we seek to develop an energy scavenger for generating power from a heat source, specifically from the body heat of an insect (beetle). The dissipated heat from the beetle body during motion, such as flight, is converted to electrical energy using a microscale thermoelectric scavenger utilizing an array of integrated thermocouples. The ultimate goal of this project is to develop a micro thermoelectric power scavenger that is capable of generating 20 - 50µ W/cm2/° C from the beetle body heat before and during flight. Flying insects can increase their body temperature by as much as 10° C during flight and dissipate much of this heat energy produced during their flight.
Title:  Mechanical Energy Scavenger for HI-MEMS
Graduate Students: Ethem Erkan Aktakka (EECS) Funding Source: DARPA Post Doc: Hanseup S. Kim (EECS) Other Investigators: Massood Z. Atashbar (EECS)	Faculty Advisor: Khalil Najafi (EECS) Work Began: 06/01/2007
Project Goals:
As ultra-low-power circuits and microsystems develop, conventional batteries used for these systems could be replaced with smaller-sized and longer-lifetime candidates. In this sense, energy harvesters hold great advantages such as unlimited lifetime, and no need for recharging or power cables. Mechanical energy harvesters are especially useful for environments that are exposed to external vibration and forces, like the wing of an insect. The goal of this research is to develop an efficient microscale power generator that harvests energy of >50µW within a volume of <0.01cc and a weight of <0.2g from live beetles as a part of the DARPA HI-MEMS (Hybrid Insect) Project. This small-energy scavenger could be used in a number of other WIMS applications.
Micropackaging, Microfabrication, and Power Source Technologies
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Title:  Smart All-Diamond Packaging for WIMS
Graduate Students: Zongliang Cao (ECE-MSU) Funding Source: WIMS ERC	Faculty Advisor: Dean M Aslam (ECE-MSU) Work Began: 08/15/2006
Project Goals:
This project’s goals are to develop a smart all-diamond packaging technology where the material for both the packaging and the interconnects is poly-C (Figure 1) and to put an energy scavenging device inside the package. It opens up the possibility of powering MEMS devices from scavenged ambient power.
Title:  Thin-Film Materials for Microsystem Technologies by Cathodic Vacuum Arc Deposition
Graduate Students: Hui Xia (MSE-MTU) Funding Source: MTU and WIMS ERC	Faculty Advisor: Paul L Bergstrom (ECE-MTU) Work Began: 08/20/2002
Project Goals:
This project investigates the use of pulsed cathodic vacuum arc deposition technique to prepare thin-film materials for MEMS applications. This technique and material development can enable the integration of microsystem devices with microelectronic processes in a CMOS-first process flow due to low-temperature characteristics of arc deposition.
Title:  Low-Temperature Microsystem Technologies by PECVD
Graduate Students: Jianlin Liang (ECE-MTU) Funding Source: MTU and WIMS ERC	Faculty Advisor: Paul L Bergstrom (ECE-MTU) Work Began: 09/01/2002
Project Goals:
This project explores the development of MEMS and microsystem devices through low-temperature, thin-film deposition techniques. The specific goals are to produce MEMS device quality materials with desirable properties compatible with other mainstream microelectronic and microsystem process technologies. This material development would lead to integrating microsystem devices with microelectronic processes in a CMOS-first process flow [1–3].
Title:  Vibration Isolation and Shock Protection Technologies for MEMS
Graduate Students: Sang Won Yoon (EECS) Funding Source: DARPA-HERMIT Post Doc: Sang Woo Lee (EECS) Other Investigators: Noel C. Perkins (ME)	Faculty Advisor: Khalil Najafi (EECS) Work Began: 01/01/2004
Project Goals:
The environment has a profound impact on the performance and the reliability of micromachined devices. Especially as performance levels are increased, the need for protection against environmental conditions becomes more pronounced. One major environmental condition is external mechanical disturbances such as vibration and shock. These disturbances may affect the devices by inducing undesirable errors that are uncorrectable with electronics, long-term device-performance degradation, or permanent damage. To protect the devices from these unwanted effects, it is important to isolate it from mechanical vibrations and shocks. This project seeks to develop generic micropackaging technologies that provide mechanical isolation and protect against severe shock for microsystems and microinstruments such as inertial sensors and resonators.
Title:  Scaling and Process Integration Challenges in Micro-EDM Technology
Graduate Students: Mark T. Richardson (EECS), Scott R. Green (ME) Funding Source: Sandia National Labs/WIMS ERC	Faculty Advisor: Yogesh B Gianchandani (EECS) Work Began: 06/01/2004
Project Goals:
The goals of this project are to study the effects of high-density µEDM batch machining on precision and throughput and to refine process integration between µEDM and the LIGA process. This will lead to direct improvements in batch-mode µEDM machining for devices such as cardiovascular stents [1] and DC-to-DC boost converters [2].
Title:  Gold-Silicon Eutectic Wafer-Bonding Technology for Vacuum Packaging
Graduate Students: Jay S. Mitchell (ME) Funding Source: WIMS ERC Other Investigators: Gholamhassan R. Lahiji (EECS)	Faculty Advisor: Khalil Najafi (EECS) Work Began: 09/01/2000
Project Goals:
Low-cost, simple, and reproducible hermetic/vacuum packaging technologies are required for many microsystems, including resonant devices and RF MEMS. Several groups, including ours, are developing new techniques for implementing small packages [1–4]. Most of these involve bonding of two wafers, a package (cap) silicon/glass wafer, and a device silicon wafer. Several wafer-bonding techniques, including adhesive, glass frit, solder, eutectic, silicon fusion/direct, and anodic bonding have been used. Of these, eutectic bonding is one of the most attractive because it is easy to use, it forms a soft eutectic to allow bonding over non-planar surfaces, and it can be done at slightly above the eutectic temperature (363°C). Although Au-Si eutectic has long been used for wafer bonding and packaging [1], few have reported its successful use in vacuum packaging. There are several reasons for this, including non-uniform eutectic flow, void formation, insufficient eutectic material in between wafers causing non-uniform bonding, oxidation of bond surfaces, and poor surface contact/adhesion. Furthermore, few published reports have presented data showing full wafer-level bonding [1]. This project aims at developing a uniform, high-yield, reproducible, silicon-gold eutectic wafer-level bonding technology used for vacuum encapsulation of MEMS.
Title:  An Actively Controlled Microvalve for Cooling and Drug Delivery
Graduate Students: Jong M. Park (EECS), Allan T. Evans (EECS) Funding Source: NASA, U-M Dept. of Anesthesiology Other Investigators: Srinivas Chiravuri (ANES), Gregory Nellis (ME-UW-Madison), Sanford Klein (ME-UW-Madison), Pat Roach (NASA-Ames Research Center)	Faculty Advisor: Yogesh B Gianchandani (EECS) Work Began: 01/01/2005
Project Goals:
One goal of this project is to create a micromachined actively controlled valve that is capable of operating reliably at very low temperatures (≈20K), and provides large flow area variation. Such a valve will be used on future NASA missions that require cooling with high-degree temperature stability and small-temperature gradients. Another goal of this project is to incorporate the valve technology into a low-power, drug-delivery device. Valve regulation offers size and power decreases over pump dosing of medication. This is particularly true for high-volume intrathecal drugs. Valve-based, drug-delivery systems with integrated sensors will allow patients a portable delivery solution that offers several improvements on current implantable technology.
Title:  Vacuum and Hermetic Packaging of MEMS Using Solder
Graduate Students: Warren (Neil) C. Welch (EECS) Funding Source: DARPA	Faculty Advisor: Khalil Najafi (EECS) Work Began: 10/01/2002
Project Goals:
This project seeks to develop vacuum and hermetic packaging with wafer-bonding technologies using a variety of solder materials. Packaging continues to pose a major challenge to the successful commercialization of MEMS and microsystems in many application areas. Many MEMS devices need to be packaged either in vacuum or in a hermetic environment to obtain high Q’s or good thermal isolation. The packaging itself needs to be performed at the wafer level, use a low-temperature process, occupy very little die area, and provide long-term stability and reliability. Although several techniques and materials have been used for implementing these vacuum/hermetic packages, little work has been done with solder as a wafer-bonding material for packaging MEMS. Solder provides several advantages, including low-temperature processing and compatibility with standard IC processes, which make it a good choice for packaging these devices. This project will develop low-temperature metal bonding processes that provide wafer-level hermetic packaging for RF MEMS.
Title:  Microscale Convective Flows Driven by Non-Contact Micromachined Heat Sources
Funding Source: Whitaker Foundation, University of Michigan	Work Began: 08/01/2004
Title:  Microdischarge-Based Sputter Ion Pump, Pressure Sensor, and Harsh Environment Chemical Sensor
Graduate Students: Scott A. Wright (EECS) Funding Source: WIMS ERC	Faculty Advisor: Yogesh B Gianchandani (EECS) Work Began: 06/01/2005
Project Goals:
This project is developing microdischarge-based devices to control the environment inside sealed packages, measure gas pressures, and detect chemicals in high-temperature environments. Sputter ion pumps have been used on the macroscale for high-vacuum applications and are traditionally used to pump air out of chambers [1]. This project is developing a microscale sputter ion pump which bonds metal to gases inside a sealed cavity, removing certain gases from the environment. Removing a large number of air molecules reduces the pressure inside the cavity [2] while removing select gases and leaving others purifies the environment. Microdischarges-based pressure sensors are also undergoing development. A harsh environment chemical sensor for petroleum monitoring and detection has been developed which utilizes three microdischarge-based devices. Microdischarge-based devices are attractive as they can operate at high temperatures, allowing the pump, pressure sensor, and chemical sensor to operate at or above 200°C [3].
Title:  Batch-Mode Ultrasonic Micromachining of Ceramics and Application to Sensors and Actuators
Graduate Students: Tao Li (EECS) Funding Source: WIMS ERC Other Investigators: Roma Y. Gianchandani (UM-Internal Medicine)	Faculty Advisor: Yogesh B Gianchandani (EECS) Work Began: 06/01/2003
Project Goals:
This project develops the batch-mode ultrasonic micromachining process which can achieve transfer of lithographic patterns onto hard, brittle, and non-conductive materials such as ceramics (including PZT) and glass. The developed process is then used to create a micromachined biopsy tool with integrated sensors to provide real time guidance for the medical procedure of fine needle aspiration (FNA) biopsy.
Title:  Low-Power Thermal Isolation for Environment-Resistant Microinstruments
Graduate Students: Sang-Hyun Lee (EECS) Funding Source: DARPA Post Doc: Sang Woo Lee (EECS)	Faculty Advisor: Khalil Najafi (EECS) Work Began: 01/01/2004
Project Goals:
The environment has a profound impact on the performance of precision micromachined instruments increasingly needed in many applications. To realize the potential of MEMS, it is critical that the environment, especially temperature, around the instrument be controlled. External temperature can easily corrupt the output of an instrument, and can induce long-term undesirable effects that are not easily correctable using electronics. An effective approach to overcome this temperature sensitivity is to control/maintain temperature using a micro-oven. In order to achieve low-power consumption for micro-oven control, a very high thermal isolation is needed. This project seeks to develop a new thermal isolation package, and a generic assembly approach for instrument-platform integration.
Title:  Non-Contact Microfluidic Manipulation Using Marangoni Flows
Graduate Students: Amar S. Basu (EECS) Funding Source: SRC, DARPA, Whitaker Foundation, University of Michigan	Faculty Advisor: Yogesh B Gianchandani (EECS) Work Began: 09/01/1997
Project Goals:
This project focuses on the use of micro- and millimeter-scale heat sources to generate Marangoni flows for the purposes of non-contact microfluidic manipulation. The goals are to understand the mechanisms of Marangoni flow, to engineer the flow geometries to perform useful fluidic functions, and finally, develop a programmable system for performing assays with water-in-oil microdroplets.
Title:  FIB-Patterned Single Electron Transistors and Nanoporous Materials Development
Graduate Students: P. Santosh K. Karre (ECE-MTU), Shwetha D. Bolagond (ECE-MTU) Funding Source: DARPA MTO / ARL Other Investigators: Craig R. Friedrich (ME-MTU)	Faculty Advisor: Paul L Bergstrom (ECE-MTU) Work Began: 09/01/2003
Project Goals:
The research will produce a focused ion beam (FIB)-based process flow for room-temperature, single-electron transistor (SET) device development and will assess the impact of FIB-etch and deposition capabilities on the structures that are formed. A detailed fabrication process flow will be documented, and the formation of a SET device by focused ion beam processing will be demonstrated. Nano sensors based on the room-temperature operating SET will be investigated.
Title:  Micromachined Joule-Thomson Cryosurgery Probe
Graduate Students: Weibin Zhu (ME) Funding Source: NIH Other Investigators: Gregory Nellis (ME-UW-Madison), Sanford Klein (ME-UW-Madison)	Faculty Advisor: Yogesh B Gianchandani (EECS) Work Began: 07/01/2003
Project Goals:
The goal of this project is to create a miniature micromachined cryosurgical probe based on silicon micromachining technology that can reach a temperature of 150K with at least 10W cooling power.
Title:  Poly-C Micro and Nano Resonators
Graduate Students: Jing Lu (ECE-MSU) Funding Source: WIMS ERC	Faculty Advisor: Dean M Aslam (ECE-MSU) Work Began: 01/01/2006
Project Goals:
The goals of this project are to (a) design, fabricate, and test poly-C micro and nano resonators for sensors and wireless interfaces; (b) improve quality factor and output impedance using novel resonator devices.
Title:  Smart All-Diamond Packaging for WIMS - MP
Funding Source: WIMS ERC	Faculty Advisor: Dean M Aslam (ECE-MSU) Work Began: 08/15/2006
Project Goals:
This project's goals are to develop a smart all-diamond packaging technology where the material for both the packaging and the interconnects is poly-C (Figure 1) and to put an energy scavenging device inside the package. It opens up the possibility of powering MEMS devices from scavenged ambient power.
Title:  A MICRO TE CRYOGENIC COOLER FOR MEMS
Funding Source: DARPA	Work Began: 03/01/2006
Title:  A Micro Thermoelectric Cryogenic Cooler for MEMS
Graduate Students: Andrew J. Gross (EECS), Niloufar Ghafouri (EECS), Baoling Huang (ME), Gisuk Hwang (ME) Funding Source: DARPA Post Doc: Hanseup S. Kim (EECS), Sang Woo Lee (EECS) Other Investigators: Massoud Kaviany (ME), Ctirad Uher (PHYS), Clark T. Nguyen (EECS-Berkeley)	Faculty Advisor: Khalil Najafi (EECS) Work Began: 03/01/2006
Project Goals:
A micro thermoelectric cryogenic cooler can have a major impact on critical military, medical, and consumer applications including substantial performance improvement of existing systems such as infrared detectors for military applications and localized quenching of biological tissues. Although thermoelectric cooling is robust and maintenance free, it has not been commonly used for macroscale cooling due to low efficiency. However, for micro/nanoscale applications, efficiency may not be the most important technical consideration; rather size and power become major issues. The micro thermoelectric cooler with non-moving parts would be the most reliable and robust system for a large section of MEMS or IC-based microsystems. The quality factor of MEMS resonators improves drastically as a function of temperature, just as the thermal noise in circuits, such as low-noise amplifiers and sensor buffers, also reduces significantly with temperature. The ultimate goal of this project is developing a multistage micro thermoelectric cryogenic cooler capable of achieving a temperature of 160K, heat lift of up to a maximum of 5mW within a volume of less than 0.2cc, and using less than 100mW of power.
Title:  Wireless Monitoring of Intraluminal Prostheses
Graduate Students: Scott R. Green (ME), Mark T. Richardson (EECS) Funding Source: WIMS ERC, NSF GRF	Faculty Advisor: Yogesh B Gianchandani (EECS) Work Began: 06/01/2006
Project Goals:
This project seeks to apply batch fabrication methodologies in the design and fabrication of stents with wireless integrated sensors. This integrated functionality will provide a direct method for monitoring the continued patency of the stented vessels and ducts, enabling timely intervention and allowing the avoidance of unnecessary procedures.
Title:  Flight Initiation and Directional Flight Control of Beetles Using Bulk Micromachined Actuators
Graduate Students: Naveen K. Gupta (ME), Karthik Visvanathan (ME) Funding Source: DARPA	Faculty Advisor: Yogesh B Gianchandani (EECS) Work Began: 12/05/2006
Project Goals:
This project aims at refining the ultrasonic machining technology for micromachining of bulk materials, such as, ceramics, PZT, glass, etc. One of the applications for which this technology is being targeted is, “flight actuation and directional flight control of the beetles” using micromachined actuators.
Title:  This is a test.
Funding Source: WIMS ERC	Work Began: 09/01/2007
Title:  High-Force and Large-Deflection Electrostatic Hydraulic Microactuators
Graduate Students: Seunghyun Lee (EECS) Funding Source: WIMS ERC Post Doc: Hanseup S. Kim (EECS)	Faculty Advisor: Khalil Najafi (EECS) Work Began: 01/01/2007
Project Goals:
High-performance microactuators have become increasingly critical components in many emerging microsystems, such as for telecommunication, rapid diagnostics of environments and health, and space exploration, as they provide unique, low-volume, low-power, and accurate interface among physical, fluidic, and electrical systems in the micro domain. Especially, electrostatic actuators have been the most widely used due to easy fabrication, low-power consumption, high-speed response, and compatible interface with electronic systems; however, their performance has been mitigated due to the inherent trade-offs between the produced force and deflection: the electrostatic pulling force between the two electrodes becomes weak when the gap distance becomes wide to maximize the deflection distance. In this project, we propose to improve the performance of an electrostatic actuator for high-force and large-deflection applications by taking advantages of high-dielectric constant and hydraulic momentum of fluids. The goals of this research are: 1) to develop microstructures and fabrication technologies that incorporate liquids for hydraulic systems and 2) to demonstrate its operation, such as high force and large deflection, in the WIMS Environmental Monitoring Testbed.
Environmental Sensors & Subsystems
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Title:   Growth of Conformal CNT Adsorbent Layers for a Micro GC and Sensors
Graduate Students: Aixia Shao (ECE-MSU) Funding Source: WIMS ERC Other Investigators: Edward T. Zellers (EHS)	Faculty Advisor: Dean M Aslam (ECE-MSU) Work Began: 08/15/2006
Project Goals:
This project seeks to develop a technology for conformal deposition of high-density carbon nanotubes (CNTs) as adsorbent materials in the micropreconcentrator focuser (µPCF) module of the WIMS micro gas chromatograph (µGC). The work investigates the effect of synthetic conditions on CNTs adsorption and desorption properties and optimizes their performance.
Title:  A Micromachined WIMS Vacuum Pump - ENV
Funding Source: WIMS ERC Post Doc: Hanseup S. Kim (EECS) Other Investigators: Peter D. Washabaugh (AERO), Luis P. Bernal (AERO)	Faculty Advisor: Khalil Najafi (EECS) Work Began: 01/01/2001
Project Goals:
An efficient, high-flow, high-pressure, low-power, and small vacuum micropump is needed in a micromachined gas chromatograph (µGC) to support the two operation modes of the µGC: sampling and analysis. However, previous gas micropumps have shown only limited capabilities, such as low flow-rate, low pressure, and large volume, thus failing to meet the requirements of the WIMS µGC. Therefore, the goals of this research are: 1) to develop a high-performance vacuum micropump overcoming the limitations of previous micropumps, and 2) to demonstrate its operation in the WIMS environmental monitoring testbed.
Title:  Testing and Evaluation of Microfabricated Columns
Graduate Students: Shaelah M. Reidy (CHEM), Gustavo Serrano (EHS) Funding Source: NASA ASTID Other Investigators: Edward T. Zellers (EHS), Katharine T. Beach (EECS)	Faculty Advisors: Work Began: 11/01/2001
Project Goals:
This project explores the use of high-performance, microfabricated columns with independent heating and temperature sensing for use in the development of a comprehensive, two-dimensional GC (GCxGC).
Title:  Chemometric and Physicochemical Modeling of a MicroGC With Sensor-Array Detector
Graduate Students: Chunguang Jin (EHS) Funding Source: WIMS ERC	Faculty Advisor: Edward T Zellers (EHS) Work Began: 09/01/2001
Project Goals:
This project seeks to develop chemometric methods and physicochemical models that address critical operational and data analysis functions needed to guide the development and allow the implementation of the WIMS µGC.
Title:  Designed Materials for an Integrated Vapor Preconcentrator
Graduate Students: Rebecca Veeneman (CHEM), Aixia Shao (ECE-MSU) Funding Source: WIMS ERC Other Investigators: Dean M. Aslam (ECE-MSU)	Faculty Advisor: Edward T Zellers (EHS) Work Began: 09/01/2000
Project Goals:
This project seeks to characterize and model the performance of high-surface-area adsorbent materials for use in capturing and thermally desorbing multiple vapors in the micropreconcentrator-focuser (µPCF) module of the WIMS µGC. Variables that determine performance, such as the adsorption capacity (We), kinetic rate coefficient (kv), and breakthrough volume (Vb) are being determined for individual vapors and simple mixtures on graphitized carbons and multiwalled carbon nanotubes (CNTs). Current µPCF devices are also being tested. Models will be used to predict Vb, guide the design, and determine the operating limits of future µPCFs.
Title:  The MicroGeiger: A Beta Particle Radiation Detector
Graduate Students: Christine K. Eun (EECS) Funding Source: WIMS ERC	Faculty Advisor: Yogesh B Gianchandani (EECS) Work Began: 09/01/2002
Project Goals:
Wireless sensing capability is particularly useful for biohazardous environmental monitoring. In areas where concern for human exposure is a priority, the added flexibility a remote sensing scheme would provide dramatically increases the usefulness of present discharge-based sensors, in particular the microGeiger. Geiger counters are the detectors of choice when it comes to on-site surveilance of radioactive material. The goal of this project is to develop a new, wireless, sensing scheme for discharge-based sensors such as micromachined Geiger counters.
Title:  Ferroelectric Film-Based High-Efficiency Microvalves and Microsensors
Graduate Students: Raghav Vanga (PHYS-MTU) Funding Source: WIMS ERC	Faculty Advisor: Miguel Levy (PHYS-MTU) Work Began: 01/01/2003
Project Goals:
The devices we propose to implement are low-power-consumption microcantilevers based on single-crystal relaxor ferroelectrics. Our aim is to utilize the large electromechanical coupling efficiency and high sensitivity of lead zinc niobate (PZN-PT) and lead-magnesium niobate (PMN-PT) film piezos to develop valve actuation, pumping drives at low-voltages (below 10V) and low-power consumption, and chemical sensors.
Title:  Sub-One-Degree Per Hour High-Performance Gyroscope
Graduate Students: Jae Yoong Cho (EECS) Funding Source: DARPA Post Doc: Sang Woo Lee (EECS)	Faculty Advisor: Khalil Najafi (EECS) Work Began: 01/01/2005
Project Goals:
Microgyroscopes are used in a variety of fields including military, automotive, guidance, and consumer products. By taking advantage of small size, high precision, highly reliable, and low-cost MEMS technology, the performance of microgyroscopes has steadily improved over the past two decades as shown in Figure 1. Currently, there are very few micro-gyroscopes with resolution as low as one-degree/hr [1]. However, it is still necessary to develop a microgyroscope with resolution below 1 degree/hr for inertial grade sensing. This project aims to develop a microgyroscope which is capable of meeting the target resolution and bias stability of sub-one-degree/hr. The micro-gyroscope will be integrated in a high-level vacuum package with superior temperature and shock immunity which is being developed under a DARPA project.
Title:  Microscale Integrated Sampler-Injector for a Micro GC
Graduate Students: Sun Kyu Kim (EHS), Rebecca Veeneman (CHEM), Jung Hwan Seo (ME) Funding Source: WIMS ERC Other Investigators: Katsuo Kurabayashi (ME)	Faculty Advisor: Edward T Zellers (EHS) Work Began: 09/01/2006
Project Goals:
This project concerns the development of a passive microfabricated integrated sampler-injector (MISI) with integral thermal desorption heater, occupying a volume of ~2.5mm3. Advantage is taken of the microscale dimensions of the device components to achieve high (pumpless) effective sampling rates, high preconcentration factors, and power-efficient desorption of ambient, volatile, organic vapors (VOCs). The goals of this project are to design, fabricate, and evaluate the performance of a prototype MISI, assess performance relative to theoretical models of diffusional transport and adsorbent capacity for vapors commonly found as contaminants in indoor working environments, and interface the sampler with an array of microsensors to determine the feasibility of incorporating the MISI into a microanalytical system for near-real-time vapor determinations.
Title:  High-Speed Chemical Sensing Using Microdischarges
Graduate Students: Bhaskar Mitra (EECS) Funding Source: WIMS ERC	Faculty Advisor: Yogesh B Gianchandani (EECS) Work Began: 01/01/2003
Project Goals:
This project explores the use of spectral emission of microdischarges for chemical analysis. On-chip microdischarges offer an efficient way to distinguish chemical composition and concentration by spectral emission detection. In the present work, we have used these for detecting metal impurities in water, organic vapors in air, and biomolecules by direct and indirect fluorescence. The devices are designed to operate without the use of a pump or carrier gas.
Title:  Breath Biomarker Determinations With a Portable Gas Chromatograph
Graduate Students: Qiongyan (Judy) Zhong (EHS), Sun Kyu Kim (EHS) Funding Source: Corporate Sponsor	Faculty Advisor: Edward T Zellers (EHS) Work Began: 08/15/2006
Project Goals:
This project is aimed at adapting a high-performance prototype, portable gas chromatograph to the detection of volatile organic compounds (VOCs) in exhaled human breath. This research explores the feasibility of monitoring a targeted set of volatile biomarkers associated with lung cancer and optimizing conditions under which the biomarkers can be separated from common background vapors and detected at sub-ppb levels.
Title:  Thiolate-Monolayer-Protected Gold Nanoparticle Sensor Films for Explosives Detection
Graduate Students: Michael P. Rowe (EHS) Funding Source: DHS Post Doc: Michael P. Rowe (EHS)	Faculty Advisor: Edward T Zellers (EHS) Work Began: 10/03/2006
Project Goals:
This project entails the development of thiolate-monolayer-protected gold nanoparticles (MPNs) as interfacial films for chemiresistor (CR) and thickness-shear-mode resonators (TSMR). Films of MPNs having novel ligand functionalities alone, or as composites with organometallic coordination complexes, are being designed and synthesized to impart high sensitivity and selectivity toward markers, tagants, and simulants of explosive substances for applications such as airport personnel and luggage screening. Testing will assess various performance features of single-transducer and multi-transducer arrays for ultimate incorporation into a µGC capable of rapid determinations of such target vapors in complex mixtures.
Title:  An Electrochemical Interface for Integrated Biosensors
Graduate Students: Yue Huang (ECE-MSU) Funding Source: Michigan Economic Development Corp.	Faculty Advisor: Andrew J Mason (ECE-MSU) Work Began: 01/05/2005
Project Goals:
This project addresses critical technical challenges in interfacing enzyme-based biosensors to integrated circuitry necessary to construct a lab-on-chip system. The integrated biosensors must provide continuous, accurate, and stable measurements of specific biochemical substance concentrations with output signals that can be conditioned on-chip and readily interfaced to off-chip data acquisition resources. This project seeks to develop and characterize an array of fully addressable, temperature-controlled electrodes integrated via post-fabrication processing on a chip containing CMOS electrochemical readout circuitry.
Title:  Fundamental Aspects of Nanoscale, Multimodal Sensor Arrays
Graduate Students: Elizabeth L. Covington (PHYS) Funding Source: DHS Post Doc: Michael P. Rowe (EHS) Other Investigators: Edward T. Zellers (EHS)	Faculty Advisor: Cagliyan Kurdak (PHYS) Work Began: 01/01/2007
Project Goals:
The project addresses challenges of miniaturizing vapor sensors employing monolayer-protected, Au-thiolate nanoparticles (MPN) as interface layers on transducers formed from simple, interdigital electrodes. An emphasis is placed on detection of explosives, tagants, and related compounds. Fundamental limits of detection will be defined by combining measurements of noise and vapor sensitivity from a wide range of MPNs and transducer dimensions. The multimodal operation (i.e., simultaneous measurements of resistance and capacitance) of the sensors will also be explored.
Title:  On-Chip Auto Calibrating Impedance Analysis for Gas Sensors
Graduate Students: Daniel J. Rairigh (ECE-MSU), Chao Yang (ECE-MSU) Funding Source: Department of Homeland Security	Faculty Advisor: Andrew J Mason (ECE-MSU) Work Began: 01/01/2007
Project Goals:
Chemiresistors (CR) coated with Au-thiolate monolayer protected nanoparticles (MPN) exhibit a highly sensitive resistance change in response to absorbed vapors and provide extremely low detection limits to vapors. The practical limitations to MPN-based CR sensor resolution are due to the precision of measurement circuits and noise sources in the transducer and electronics. This project aims to develop a microelectronic instrumentation circuit that will maximize measurement precision and minimize electronic noise within a platform suitable for monolithic integration of a gas sensor array microsystem. The chemiresistor also has a theoretical capacitive response which has been difficult to investigate, again due to noise and parasitics. The second goal of this project is to extend the interface circuit to allow full impedance measurements which would be able to characterize both the resistance and capacitance of the chemiresistor.
Title:  Integrated Particle Counting and Potentiometric Sensor Array for Water Quality Analysis
Graduate Students: K. Jeff Campbell (ECE-UT) Funding Source: NSF Grant	Faculty Advisor: Richard B Brown (ECE-UT) Work Began: 09/19/2005
Project Goals:
This project will implement an all-electronic potentiometric and particle sensor array. A manufacturing process which facilitates mass-fabrication of nanopore sensors atop CMOS circuitry will be developed. Integrated electronics will greatly reduce the number of external connections between sensor and instrument, reducing noise and improving power budget. The microstructure is also expected to be robust and offer improved reliability over existing sensors. Finally, the performance of completed sensors will be characterized, and the behavior of an array of sensors will be optimized.
Title:  Multi-Transducer Arrays for a Micro GC Detector
Graduate Students: Chao Xu (EHS) Funding Source: Corporate Sponsor Post Doc: Chao Xu (EHS)	Faculty Advisor: Edward T Zellers (EHS) Work Began: 09/10/2006
Project Goals:
This project explores the use of multi-transducer arrays as detectors for a µGC system. Chemiresistors (CR) and film-bulk-acoustic resonators (FBAR) coated with gold-thiolate monolayer-protected nanoparticles (MPNs) are being tested. FBARs respond to changes in film mass and CRs respond to changes in film volume and dielectric properties. The information about sorbed vapors provided by the respective transducer types is, thus, complementary. Thickness-shear-mode resonators (TSMR) are used as reference mass sensors. MPNs with different thiolate derivatives are used to impart differential affinities for different vapors [1]. Application to breath biomarkers of health status, including the compounds of low volatility, is being considered [2].
Title:  Growth of Conformal CNT Adsorbent Layers for a Micro GC and Sensors
Funding Source: WIMS ERC	Work Began: 01/01/2006
Project Goals:
This project seeks to develop a technology for conformal deposition of high-density carbon nanotubes (CNTs) as adsorbent materials in the (thermally desorbed) vapor micropreconcentrator/ focuser (¦ÌPCF) module of the WIMS micro gas chromatograph (¦ÌGC). The work investigates the effect of synthetic conditions on CNTs adsorption and desorption properties and optimizing their performance.
Title:  A MEMS Gas Chromatograph
Graduate Students: WIMS EMT Team Funding Source: WIMS ERC Other Investigators: Robert J. Gordenker (EECS)	Faculty Advisor: Edward T Zellers (EHS) Work Began: 09/01/2005
Project Goals:
This project concerns the assembly and optimization of a high-performance micro gas chromatograph (µGC) capable of capturing, preconcentrating, separating, and detecting the components of complex environmental vapor mixtures. An embedded µcontroller is used for system control, calibration, analysis parameter setup, sequencing instrument functions, and sensor data acquisition. Preprocessing and buffering sensor data for upload to a host controller using a ZIGBEE standard wireless link enables deployment of multiple µGC systems under control of a single user.
Title:  A Microfabricated Thermal Modulator for Low-Power, Low-Volume, Two-Dimensional Gas Chromatography (GCxGC)
Graduate Students: Sung Jin Kim (ME) Funding Source: NASA Other Investigators: Edward T. Zellers (EHS), Kensall D. Wise (EECS)	Faculty Advisor: Katsuo Kurabayashi (ME) Work Began: 04/01/2006
Project Goals:
The goal of this project is to develop a key subcomponent of the microfabricated GCxGC system, a thermal modulator (TM), using MEMS technology. In general, TMs are crucial to achieve high sensitivity in the GCxGC system by providing 10-to-50-fold detection enhancement. This project aims to design, fabricate, and test a MEMS-based thermal modulator that can be integrated with microfabricated 2-D GC columns and generate heating and cooling cycles between -50°C and 200°C within a few hundred millisecond timescales. A microfabricated heater pattern is used for heating, and cooling is achieved by conduction to a cold surface. Thermal resistance to the cold surface can be tailored using air-gap insulators. Significant technological advances are being explored to reduce space, mass, and power resources required for the organic vapor separation process with a MEMS-based TM device. The system incorporating the TM provides the opportunity to conduct complex in situ sample analysis with minimal temperature-control requirements.
Title:  Research to Practice: Reliability of Microfabricated GC Columns
Graduate Students: Gustavo Serrano (EHS), Shaelah M. Reidy (CHEM) Funding Source: WIMS ERC	Faculty Advisor: Edward T Zellers (EHS) Work Began: 01/15/2007
Project Goals:
The aims of this project are: to assess the consistency of chromatographic resolution achievable from multiple microfabricated glass/Si separation columns statically coated with non-polar and polar stationary phases; to develop better polar and non-polar coating techniques with surface pre-treatment methods; and to evaluate the effect of thermal cycling in an air matrix.
Title:  Growth of Conformal CNT Adsorbent Layers for a Micro GC
Funding Source: WIMS ERC	Work Began: 08/15/2006
Project Goals:
This project seeks to develop a technology for conformal deposition of high-density carbon na1notubes (CNTs) as adsorbent materials in the (thermally desorbed) micropreconcentrator focuser (¦ÌPCF) module of the WIMS micro gas chromatograph (¦ÌGC). The work investigates the effect of synthetic conditions on CNTs adsorption, desorption properties and optimizes their performance.
Title:  Integrated Porous Silicon Technology for a Micro Gas Chromatograph (µGC)
Graduate Students: Lakshman Kumar Vanga (ECE-MTU), Rodney R. Snow (ECE-MTU) Funding Source: WIMS ERC Other Investigators: Edward T. Zellers (EHS)	Faculty Advisor: Paul L Bergstrom (ECE-MTU) Work Began: 10/09/2005
Project Goals:
The goal of this research is to develop porous silicon technology for three devices: the inlet particulate filter, on-board calibration standard vapor source, and a novel preconcentrator/focuser device (PCF) for the micro gas chromatograph (µGC) in the Environmental Monitoring Testbed. The preconcentrator/focuser device is a two-layered structure as shown in Figure 1. The two-layered structure consists of a diffusive channel made of porous silicon (PS) and a cavity region to hold the preconcentrator materials (adsorbents). The prominent features of the design include the effective sampling of the gas species and power-efficient desorption of volatile vapors. The design aims to produce desirable results at powers as low as 300mW. Different microheater designs will be considered that can heat up the adsorbents to 250°C–300°C and can effectively desorb the gas vapors in seconds.
Title:  A Microscale Integrated Sampler-Injector for a Micro GC
Funding Source: WIMS ERC	Work Began: 09/01/2007
Title:  Integrated Low-Power, High-Pressure, High-Flow Gas Micropump
Graduate Students: Seunghyun Lee (EECS), Seow Yuen Yee (EECS) Funding Source: WIMS ERC Post Doc: Hanseup S. Kim (EECS) Other Investigators: Luis P. Bernal (AERO)	Faculty Advisor: Khalil Najafi (EECS) Work Began: 01/01/2007
Project Goals:
An efficient, low-power, high-flow, high-pressure, and small gas micropump is needed in many emerging microsystem applications, such as a micromachined gas chromatograph µGC). Especially the WIMS µGC needs a pump that supports the two different operation modes of the µGC: sampling and analysis. Previous gas micropumps have shown only limited capabilities, such as low-flow-rate, low pressure, and large volume, thus failing to meet the requirements of the WIMS µGC. In a recently completed project, a micromachined pump has been developed and has demonstrated for the first time that a much higher flow rate and pressure could be produced. In this project, we propose to continue developing this micropump to achieve still a higher pressure and higher flow rate than achieved to date. The goals of this research are: 1) to develop a high-performance gas micropump overcoming the limitations of previous micropumps and 2) to demonstrate its operation in the WIMS Environmental Monitoring Testbed.
Title:  A Low-Volume, Low-Power, Preconcentration and Separation System
Graduate Students: Rebecca Veeneman (CHEM), Shaelah M. Reidy (CHEM) Funding Source: WIMS ERC Other Investigators: Edward T. Zellers (EHS)	Faculty Advisor: Kensall David Wise (EECS) Work Began: 06/01/2007
Project Goals:
A truly low-power, low-dead-volume, high-speed gas separation system continues to be one of the long-term goals of the WIMS ERC. Achieving this goal has been hampered by fluidic interconnects that require capillary lines since these increase system size and power and also create cold spots that lead to band broadening and reduced separation. The goal of this project is to eliminate the need for capillary connections between the preconcentrator, separation columns, and detector, realizing an integrated three-chip separation system that can be used as a building block for all future high-performance microGC systems.
Title:  Low Dead Volume Gas Detection System
Funding Source: ERC Other Investigators: Katharine T. Beach (EECS)	Faculty Advisor: Kensall David Wise (EECS) Work Began: 06/01/2007
Project Goals:
The intergration of the varoius components that make up the Environmental Testbed has been one of the long term goals of the WIMS ERC. This goal has been hampered by interconnection issues that have required long lines of capillary tubes. This project focuses on eliminating the need for capillary connection between the miro preconcentrator and GC. Goals: Lower mass/power precon, more robust CVD GC,choose your size pre-con, complete separation part of the system that is small and low power, increased device yield,
Title:  A Micromachined Vacuum Pump
Graduate Students: Seunghyun Lee (EECS), Seow Yuen Yee (EECS), Mahdi Sadeghi (EECS) Post Doc: Hanseup S. Kim (EECS)	Faculty Advisor: Khalil Najafi (EECS) Work Began: 04/01/2008
Biomedical Sensors & Subsystems
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Title:  All-Diamond Probes for Neural Applications
Graduate Students: Ho-Yin Chan (ECE-MSU) Funding Source: WIMS ERC Other Investigators: Kensall D. Wise (EECS)	Faculty Advisor: Dean M Aslam (ECE-MSU) Work Began: 09/01/2006
Project Goals:
This project focuses on design, fabrication, and testing of an all-diamond probe based on poly-crystalline (poly-C) diamond. It also focuses on developing and improving poly-C technology for other biomedical and electrochemical applications, such as neural probes and electrodes.
Title:  Diffusion Based Microgradient Array
Funding Source: WIMS ERC	Work Began: 09/01/2004
Title:  A Micromechanical Cochlear Processor
Graduate Students: Wen-Lung Huang (EECS) Funding Source: WIMS ERC	Faculty Advisor: Clark T.-C. Nguyen (EECS-Berkeley) Work Began: 09/01/2000
Project Goals:
This project entails the design and demonstration of a micromechanical frequency selector for cochlear signal processing. Such a micromechanical frequency selector has the potential advantages of better selectivity than electronic versions and zero dc power consumption. The long-term vision here is a signal-processing device capable of attaining speed and dynamic range similar to that of the biological cochlea.
Title:  Cortical Mapping Using Lithography-Based Microelectrode Arrays
Graduate Students: Gregory J. Gage (BME), Hirak Parikh (BME), Timothy Marzullo (BME), Azadeh Yazdan-Shahmorad (BME), Kip A. Ludwig (BME) Funding Source: WIMS ERC, NIH	Faculty Advisor: Daryl R Kipke (BME) Work Began: 03/01/2005
Project Goals:
The goals of this project are: 1) To characterize the laminar structure of cortical columns during motor learning and to investigate the use of local field potentials at specific layers of the cortex for use in brain machine interface tasks; 2) To study the spatio-temporal dynamics of the joint activity and quantify the information that can be obtained from LFP and spiking activity during planning and movement phases; and 3) Investigate non-invasive electrocortiogram (ECoG) recordings and their relationship with the cortical recordings.
Title:  A Chronic Drug-Delivery Probe With Integrated Microvalves and Closed-Loop Circuitry
Graduate Students: Kyusuk Baek (EECS) Funding Source: NIH/NCRR and WIMS ERC Other Investigators: Sanford C. Bledsoe (OTO)	Faculty Advisor: Kensall David Wise (EECS) Work Began: 05/01/2001
Project Goals:
The goal of this research is to incorporate an integrated drug-delivery system, including microchannels, flowmeters, and microvalves, into an active chronic probe. The recording sites of the probe will make it possible to acquire high-density images of electrical activity in the brain. The drug-delivery system will manipulate these images by delivering pharmaceuticals to the target volume of tissue. The desired chemicals will be directed to the proper sites under the control of microvalves to allow multisite multichemical injection while minimizing the fluidic lead count. The overall structure will be compatible with on-chip circuitry to actuate the valves, control drug delivery, and provide feedback to the system on the basis of the recorded action potentials.
Title:  Front-End Engineering of Neural Recording Microsystems for Neuroscience & Neural Prostheses
Graduate Students: Gayatri E. Perlin (EECS) Funding Source: NIH/NINDS and WIMS ERC	Faculty Advisor: Kensall David Wise (EECS) Work Began: 01/01/2003
Project Goals:
Silicon micromachined electrode arrays are nearing the point where they are ready for use in prostheses aimed at a number of neurological disorders, including deafness, paralysis, blindness, epilepsy, and Parkinson’s disease. Silicon processing has become the enabling technology for high-density electrode arrays, and using silicon-based micromachining, various recording and stimulating probes have been created over the past three decades. Still, there is an increasing demand for arrays having dozens or hundreds of sites and interest in using multiple sites both to allow improved understanding of biological neural networks and for the implementation of neural prostheses. This project contributes to the larger effort in developing an implantable wireless microsystem for use in neuroscience and neural prostheses at the front-end (the microelectrodes and signal conditioning circuitry). The work spans three general areas: 1) advanced electrode engineering for improved electrode-cell coupling and chronic compatibility, 2) robust front-end signal conditioning circuit design, and 3) integration and packaging of the electrodes and circuit chips. Electrodes having recording and/or stimulating sites available on both sides of the substrate have been developed to study and improve cell coupling in tissue. Lattice-structured shanks have been engineered to reduce micromotion-related tissue response in chronic applications. Advances in three-dimensional arrays of electrodes and their assembly techniques resulting in zero-rise compact structures have been made. A programmable neural recording front-end signal conditioning ASIC has been successfully developed. A low-profile platform is in development for the integration of the electrode arrays and the electronics comprising the neural recording microsystem.
Title:  Microscale Convective Flows Driven by Non-contact Micromachined Thermal Probes
Funding Source: Whitaker Foundation, University of Michigan	Work Began: 08/01/2004
Title:  Neurochemical Sensing with MEMS-Based Microelectrode Arrays
Graduate Students: Matthew D. Gibson (BME), Robert K. Franklin (EECS), Luis G. Salas (BME) Funding Source: NIH Other Investigators: Matthew D. Johnson (BME), Richard B. Brown (ECE-UT)	Faculty Advisor: Daryl R Kipke (BME) Work Began: 09/01/2003
Project Goals:
Many disabling brain disorders manifest themselves in abnormal electrophysiological activity, as well as abnormal fluctuations of neurotransmitters. The major outcome of this project is the development and application of MEMS-based neural probe systems for multichannel, neurochemical, and electrophysiological sensing in-vivo. Significant tasks include: 1) developing site-specific coating techniques for high sensitivity and selectivity to specific neurochemicals, 2) developing hardware for simultaneous multichannel neurochemical recordings, and 3) investigating interventional strategies to prolong implanted neurochemical probe lifetimes. This probe technology may provide scientists and clinicians with a more robust picture of neuronal activity and enable more effective therapeutic strategies.
Title:  Advanced Neural Interfaces
Graduate Students: Taegyun Moon (BME), John P. Seymour (BME), Erin K. Purcell (BME) Funding Source: WIMS ERC Post Doc: Jeyakumar Subbaroyan (BME)	Faculty Advisor: Daryl R Kipke (BME) Work Began: 09/01/2003
Project Goals:
The longevity of neural prosthetics may be greatly improved by optimizing the tissue electrode interface. Studies have shown that microglia, astrocytes, and extracellular matrices can form encapsulation layers and, in some cases, electrically shield a neural probe’s electrode sites from healthy neural tissue [1, 2]. The reactive tissue response at the neural interface includes both an early anti-inflammatory response due to insertion trauma and a sustained response induced in part by the interplay among micromotion [3], tethering, and device biocompatibility [4, 5]. The longevity of the neural electrode implant has been limited by this reactive tissue encapsulation of the implant [5-7]. The goal of this project is to minimize the reactive tissue response and its effects on the recording capabilities.
Title:  A Cochlear Prosthesis Insertion Device Based on a Retractable and Active Insertion Tool
Graduate Students: Radheshyam Tewari (MEEM-MTU) Funding Source: WIMS ERC	Faculty Advisor: Craig R Friedrich (ME-MTU) Work Began: 09/14/2007
Project Goals:
Commercially available cochlear electrodes are implanted with the aid of a passive insertion tool. The insertion tool helps guide the electrode array inside the scala tympani chamber of the cochlea. Such insertion tools could facilitate both the larger insertion depths and the electrode array proximity with the cochlear modiolus if active. Undoubtedly, in the post implantation phase, the fundamental use of such an insertion tool is only to facilitate a stiff structural backing and hence the required rigidity to the implant for maintaining the perimodiolar shape of the later. The dependency of the implant’s performance on the insertion tool makes it mandatory to leave the insertion tool after the implantation. The tool results in bulkier devices making the fluid-filled tympanic chamber more congested. This project aims to develop a new cochlear prosthesis insertion device consisting of a completely retractable insertion tool.
Title:  A Microsystem for Neurochemical Sensing
Graduate Students: Robert K. Franklin (EECS) Funding Source: NIH NIBIB Grant EB005022-01A1 Other Investigators: Daryl R. Kipke (BME)	Faculty Advisor: Richard B Brown (ECE-UT) Work Began: 01/01/2005
Project Goals:
The goal of this project is to develop a fully implantable, neurochemical monitoring microsystem based on MEMS brain-probe technology developed at the University of Michigan.
Title:  Development of an Oxygen Microgradient Chip
Graduate Students: Jaehyun Park (EECS), Tushar Bansal (EECS) Funding Source: Faculty Start-up Funds	Faculty Advisor: Michel Martin Maharbiz (EECS) Work Began: 09/01/2003
Project Goals:
The oxygen microenvironment within tissue plays a crucial role in many biological processes and the treatment of many diseases. No technology currently exists that allows the researcher to control localized oxygen doses and impose arbitrary oxygen gradients within tissue with microscale resolution. Our primary goal is to develop an oxygen microgradient chip that allows control of the oxygen environment in a tissue sample or microbial culture with microscale spatio-temporal resolution. Our fabricated device generates 1-D and 2-D dissolved oxygen gradients across several millimeters with microscale precision and has the potential to test the effect of localized oxygen delivery on a wide range of tiny animals, tissues, and cell samples. Importantly, user-defined microgradient profile is generated at the time of the experiment, adjustable during the course of an experiment, and actively responsive to transient experimental conditions.
Title:  A Wireless Implantable Microsystem for Multichannel Neural Recording
Graduate Students: no graduate student Funding Source: WIMS-ERC, NIH/NINDS Other Investigators: Khalil Najafi (EECS)	Faculty Advisor: Kensall David Wise (EECS) Work Began: 10/01/2004
Project Goals:
Chronic recording of multichannel neural electrical activity using microprobes is extensively used for understanding the operation of the nervous system and for implantable prostheses. This project deals with the design and implementation of an implantable microsystem for wireless recording of neural signals. The system uses a bidirectional inductively coupled RF telemetry link, providing power and control to the implant in the forward direction and transmitting recorded neural signals to the outside world in the reverse direction. Figure 1 illustrates the general architecture of the wireless implantable microsystem.
Title:  A High-Density Mechanically Robust Cochlear Electrode Array With Multiple Site Configurations
Graduate Students: Angelique C. Johnson (EECS) Funding Source: WIMS ERC Other Investigators: Teresa A. Zwolan (OTO), Craig R. Friedrich (ME-MTU)	Faculty Advisor: Kensall David Wise (EECS) Work Began: 05/01/2006
Project Goals:
This project is developing a 128-site, 16-channel, electrode array as a cochlear prosthesis for the profoundly deaf. By placing the electrical stimulation sites in a high-density configuration (250µm pitch), this device offers the potential for greater frequency resolution, leading to enhanced speech recognition. In creating the electrode array, planar IC processing techniques will be investigated to diminish the issues surrounding array fabrication. Full or partial polymer substrates will be investigated to increase the robustness of the cochlear array and the cable that interfaces it to the electronics. A low-stress, low-resistance, multilevel, metal scheme will also be created to handle routing from electrode sites to current stimulator circuitry. One main issue in the realization of a cochlear array fabricated using IC processing techniques is the backing and insertion mechanisms that need to be integrated with the array for mechanical stability and modiolar hugging capabilities. In this project, a two-in-one system for backing/insertion of the array will be investigated. System-level issues including biphasic stimulus current generation, built-in self-test, adaptive stimulus amplitude control based on neural response recordings, versatile electrode configuration capabilities, and array position information will be addressed.
Title:  Force Characterization and Rigidity Analysis of a Monolithic Cochlear Prosthesis Actuator
Graduate Students: Radheshyam Tewari (MEEM-MTU) Funding Source: WIMS ERC	Faculty Advisor: Craig R Friedrich (ME-MTU) Work Began: 07/01/2006
Project Goals:
Cochlear implants have evolved as a great aid for patients suffering from profound deafness. Primarily, the implant is made to wrap around the modiolus of the cochlea with the help of an insertion tool, positioning it deeper and more controllably during the surgical implantation. Although surgical methods are well developed, possibilities that the device is pushed through other intricate structures in the cochlea are not fully eliminated. Any internal damage caused by insertion tool stiffness, or mechanical failure of the device itself due to low rigidity of the tool can raise the risk of trauma, possibly losing residual hearing and further nerve degeneration. The goal of this project was to measure the rigidity of the tool and to characterize the wall contact forces inserted by the tool under different working pressures during actuation.
Title:  A Neural Stem Cell-Seeded Hydrogel Coating for Chronic Neural Probes
Funding Source: MEDC and NSC	Work Began: 06/01/2004
Project Goals:
1. Successfully seed and maintain viable, undifferentiated neural stem cells in an alginate hydrogel scaffold. 2. Determine the optimal scaffold composition for the cells based on the best combination of viability, growth factor release, and mechanical stability. 3. Using the chosen scaffold composition, demonstrate a reduced glial response in seeded, coated probes versus hydrogel-alone coated probes, cells alone with probe, and probe alone controls. 4. Demonstrate improved long-term recordings with seeded, coated probes versus controls.
Title:  Frequency Modulation of Local Field Potentials in Rat Cortex
Funding Source: WIMS ERC	Work Began: 07/01/2005
Title:  A Neural Probe With Integrated Polymer-Gold Electrostatic Actuator for Chronic Drug Dosing
Graduate Students: Meng-Ping Chang (ME), Tushar Bansal (EECS) Funding Source: WIMS ERC	Faculty Advisor: Michel Martin Maharbiz (EECS) Work Began: 01/01/2006
Project Goals:
The goal of this project is to design and fabricate a neural probe integrated with polymer-gold (PoGo) electrostatic actuators (Figure 1) that can be run at a low voltage (less than 15 volts). We have designed and fabricated a demo version of the PoGo actuator. This PoGo device functions as both pumps and valves for liquid transport in the neural probe. Our goal is to reduce the operating voltage to less than 5 volts, and the power consumption to less than 100pW.
Title:  A Wireless Sub-Microwatt Intraocular Pressure Sensor
Graduate Students: Razi-ul M. Haque (EECS) Funding Source: WIMS ERC Other Investigators: Dennis M. Sylvester (EECS)	Faculty Advisor: Kensall David Wise (EECS) Work Began: 01/03/2006
Project Goals:
This project explores technologies that when combined will demonstrate the practicality of very small, ultra-low-power, wireless implantable sensors. The target application is an intraocular pressure sensor (glaucometer) capable of autonomous data logging and powered by energy scavenging. The device demands very small size (2mm x 0.75mm), biocompatibility, and ultra-low power. It is representative of a wide range of extremely small yet useful implantable devices. Challenges include the power source and methods for recharging it, wireless transmission techniques that are efficient at low data rates, yet robust enough to transmit signals outside the body, and packaging techniques that reduce size while maintaining biocompatibility and hermeticity. The performance limits in these areas are being explored.
Title:  A Lightweight Bidirectional Wireless Neural Recording and Control Microsystem
Graduate Students: Amir Borna (EECS) Funding Source: NIH	Faculty Advisor: Khalil Najafi (EECS) Work Began: 01/01/2006
Project Goals:
Recent progress in neuroscience has been brought about by advances in many fields of science and engineering, including integrated circuit and MEMS, advanced mathematical concepts, signal processing, statistics, and of course, improved understanding of biological structures and functions. The primary goal of this project is to collect biological information from freely flying songbirds, and specifically in the Zebra Finch. To understand the role of experience in modifying the brain, songbirds are one of the best models to study due to the fact that the male specie can learn his father’s song by a process of imitation which is independent of genetic ties between the birds (S. Overduin, 2003). To collect the needed information, extracellular neural activity recorded by electrodes implanted in the host’s forebrain, should be processed and then transmitted out over a wireless link to a remote receiver by a lightweight, low-power, and long-range transceiver capable of both sending and receiving data and power.
Title:  Fixture Design for Cochlear Implant Insertion Tool
Graduate Students: Mehulkumar D. Patel (MEEM-MTU) Funding Source: WIMS ERC	Faculty Advisor: Craig R Friedrich (ME-MTU) Work Began: 10/19/2006
Project Goals:
Cochlear implantation is an established surgery for people having profound deafness. It has shown great success for restoring partial hearing capacity in the cases of profound deafness. The effectiveness of this implant is largely dependent on its deep and controlled insertion in the scala tympani chamber of the spiral-shaped cochlea. An insertion tool is needed for controlled and deep insertion of the implant’s electrode array. Surgical insertions that have been performed so far have been done manually, which requires very skilled surgeons. These manual insertions also have a greater chance for manual insertion errors. Any misalignment of the implant and the scala tympani centerline can increase the implantation difficulty. The goal of this project is to design a mechanism which can provide better control of insertions.
Title:  A 3-D Dual-Platform Mapping System for Neural Coding Studies
Graduate Students: Sister Mary Elizabeth Merriam (EECS) Funding Source: WIMS ERC and the Polly Anderson Gift Fund	Faculty Advisor: Kensall David Wise (EECS) Work Began: 07/01/2007
Project Goals:
A WIMS microsystem is being developed in order to provide neuroscientists with the necessary research devices to enable and expedite continued progress in understanding the anatomy and physiology of the brain, with particular focus on mapping the complex connections of neural circuitry. Current neural research tools for electrical impulse studies include glass pipettes and wire tetrodes. These devices have significant limitations due to their size which constrains the number of possible recording and stimulating locations, induces tissue damage, and causes device interference with neural signals. Significant advances have been made by MEMS-based recording and stimulating arrays to decrease device size and increase the number of sites per device. However, commercially available devices are confined to two-dimensional passive structures with restrictions in spatial site configurations and the potential corruption of signals due to the interconnect path length between sites and circuitry. This research is developing a system which incorporates two three-dimensional, electrode site arrays with hybrid circuitry to provide flexible stimulation/recording site selection, reduced lead count, and enhanced signal-to-noise ratio.
Title:  Nitric Oxide Micro-Gradient Generator
Funding Source: University of Michigan Regents Fellowship	Work Began: 09/01/2006
Title:  Implanted Microsystems for Cyborg Insect Flight Control
Graduate Students: Hirotaka Sato Funding Source: DARPA Post Doc: Hirotaka Sato Other Investigators: Yogesh B. Gianchandani (EECS), Khalil Najafi (EECS), Kensall D. Wise (EECS), Clark T. Nguyen (EECS-Berkeley)	Faculty Advisor: Michel Martin Maharbiz (EECS) Work Began: 10/01/2006
Project Goals:
The goals of this project are to achieve control of insect flight via implanted microsystems. Implanted electrodes are used to trigger flight under the control of an implanted processor and wireless link. The project is another example of the application of wireless microsystems using low power and small size.
Title:  New Electrode Technology for the Central and Peripheral Nervous Systems
Graduate Students: no graduate student Funding Source: WIMS ERC	Faculty Advisor: Kensall David Wise (EECS) Work Began: 10/01/2004
Project Goals:
One of the major medical challenges faced today by scientists and by the medical profession is to repair damage in the nervous system by either externally stimulating neurons (e.g., in deafness or blindness) or providing connectivity to damaged neural circuits (e.g., for paralysis caused by spinal injuries) to enable patients to live normal lives. Meeting this challenge will require the development of high-density, high-sensitivity, biocompatible electrodes with which to record neuronal signals or input signals to neural circuits. Currently, the silicon micromachined electrodes developed at the University of Michigan are arguably the most advanced neural interfaces available anywhere. The goal of this project is to develop new devices, fabrication techniques, and materials to fabricate even higher density neural probes that are more sensitive, easier to use, more biocompatible, and more robust.
Title:  Implanted microsystems for flight control of cyborg insects
Funding Source: DARPA	Work Began: 10/01/2006
Wireless Interfaces
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Title:  A Miniature High-Impedance Antenna
Graduate Students: Wonbin Hong (EECS) Funding Source: WIMS ERC	Faculty Advisor: Kamal Sarabandi (EECS) Work Began: 01/09/2001
Project Goals:
This project entails the design and demonstration of miniaturized antennas with the possibility of achieving complete integration with the RF front end, and ultimately achieving a single-chip wireless system. Reducing size while increasing the bandwidth and efficiency in presence of the ground plane will be addressed.
Title:  Low-Power Transmitter for Wireless Sensor Networks
Graduate Students: Mark A. Ferriss (EECS) Funding Source: WIMS ERC	Faculty Advisor: Michael P Flynn (EECS) Work Began: 09/01/2003
Project Goals:
The aim of this research is to develop a wireless transmitter for a low-power sensor node and develop new circuit design techniques to allow for lower power RF circuits. Existing transmitters using proprietary wireless technologies (e.g., Bluetooth) consume too much power for these applications. Consequently, this work will also focus on minimizing cost, size, complexity, and power.
Title:  A 12b 10MS/s Successive Approximation ADC in 0.13µm CMOS
Graduate Students: Joshua J. Kang (EECS) Funding Source: Analog Devices Inc.	Faculty Advisor: Michael P Flynn (EECS) Work Began: 09/02/2006
Project Goals:
As supply voltage sharply drops in deep submicron CMOS technology, single battery operation (1.2V) is possible. However, ADC precision suffers greatly as input signal level and reference level scales down, because of thermal noise and coupled digital switching noise. The goal of the project is to develop a high precision, low-power ADC in deep submicron mixed-mode CMOS technology. The charge-redistributing SAR ADC architecture is used, because it benefits from low-voltage digital CMOS technology.
Title:  A Fully Integrated CMOS Receiver
Graduate Students: Dan Shi (EECS) Funding Source: WIMS ERC	Faculty Advisor: Michael P Flynn (EECS) Work Began: 12/01/2004
Project Goals:
The rapidly growing wireless communication market is creating a growing demand for radio frequency (RF) transceivers. More and more RF bands and standards, or even the entire transceivers, have been integrated into one chip to minimize the size and cost. This project focuses on developing a wireless solution which is highly integrated with on-chip passive components and that is small in size and requires very low power. This is for applications which need short range, low-data-rate, but a long lifetime. These include wireless devices used in implantable neuroprosthetic devices, environmental wireless sensors, etc. To achieve these goals, super-regenerative architecture is used, since the power consumption is low due to the simplified transceiver architecture and relaxed performance constraints.
Title:  Digitally Corrected Folding ADCs
Graduate Students: Ivan T. Bogue (EECS) Funding Source: WIMS ERC	Faculty Advisor: Michael P Flynn (EECS) Work Began: 09/01/2002
Project Goals:
This work involves developing digital calibration techniques for folding analog-to-digital converters. According