Publications

Energy Measures for Sensor Networks

Lance Doherty
Kristofer S.J. Pister
Kannan Ramchandran
Ming Gu
2004
The problem of full data recovery from a sensor network of thousands of randomlyplaced nodes is addressed as it relates to the complexity of the network data. In the applications of interest, the user requires a representation of the full twodimensional data generated by a field underlying the area of the network. The usefulness of data recovery algorithms is judged by the units of energy consumption to recover sufficient data to reconstruct the field to a...

Electro Micro-Metrology

Jason Clark
Kristofer S. J. Pister
James Demmel
Sanjay Govindje
Luke P. Lee
2005
Electro Micro-Metrology (EMM) is a novel methodology for precision metrology, sensing, and actuation at the micro- and nano-scale. EMM is well-suited for tiny technology because it leverages off the electromechanical benefits of the scale. EMM is the method of using micro- or nano-scale devices to measure and characterize themselves, other devices, or whatever the devices subsequently interact with. By electronically measuring the change in capacitance, change in voltage, and/or resonant frequency of just a...

Devices, Structures, and Processes for Optical MEMS

Hyuck Choo
Richard S. Muller
Jeffrey Bokor
James R. Graham
2007

High-precision microlenses have been fabricated utilizing hydrophobic effects and polymer-jet printing technology. The lenses are formed precisely at desired locations on a wafer using a polymer-jet system in which hydrophobic effects define the lens diameter and surface tension creates a high-quality optical surface. They have 200–1000-μm diameters and 343–7862-μm focal lengths. At 635 nm, wavefront aberrations (measured using a Shack-Hartmann sensor of λ/100 accuracy) are λ/5-...

Biomimetic, Polymeric Transistor-Based Biosensor Technology

Jim Cheng
Albert P. Pisano
Ming C. Wu
Liwei Lin
2009

The goal of this research is the creation of robust, flexible, polymer sensors and circuits fabricated partially from the low cost biopolymer, chitosan, the deacetylated form of chitin which is the second most abundant polyssacharide in nature. Chitin is found in crustaceans, insects, bacteria and fungi. The sensors will detect diatomic gases and DNA to more complex macro molecules (e.g. exotoxins) in a fluidic or dry environment. Polymer-nanoparticle (e.g. Ge) hybrid films allow for development of robust polymer thin-film transistors and, with optimization of the hybrid film,...

Chitosan as a MEMS Engineering Material

Jim Cheng
Albert P. Pisano
Liwei Lin
2006
Since the beginning of civilization, there has been a thrust to better ourselves, to enhance our performance and capabilities. With nature as a template, a variety of sensors were created. As technology improved, artificial sensors have mostly surpassed their natural counterparts in sensitivity and size except in several specific areas, one being infrared sensing. The Melanophila acuminata, also known as the jewel beetle, is one of ...

Surface Engineering for MEMS Reliability

William Ashurst
Roya Maboudian
David B. Graves
Roger T. Howe
2003

The integration of miniaturized mechanical components with microelectronic components has spawned a new technology known as microelectromechanical systems (MEMS). This technology extends the benefits of microelectronic fabrication to sensing and actuating functions. Examples of MEMS devices that have been commercially produced include relatively simple mechanisms such as accelerometers, pressure sensors and digital mirror projectors.

Despite recent progress in micromachining capability, the realization of more complex commercial and specialized use of MEMS is challenged due to...

Actively Variable-Spectrum Optoelectronics with Black Phosphorus

Hyungjin Kim
Shiekh Zia Uddin
Der-Hsien Lien
Matthew Yeh
Nima Sefidmooye Azar
Sivacarendran Balendhran
Taehun Kim
Niharika Gupta
Yoonsoo Rho
Costas P. Grigoropoulos
Kenneth B. Crozier
Ali Javey
2021

Room-temperature optoelectronic devices that operate at short-wavelength and mid-wavelength infrared ranges (one to eight micrometres) can be used for numerous applications. To achieve the range of operating wavelengths needed for a given application, a combination of materials with different bandgaps (for example, superlattices or heterostructures) or variations in the composition of semiconductor alloys during growth are used. However, these materials are complex to fabricate, and the operating range is fixed after fabrication. Although wide-range, active and reversible tunability...

Integrated Nanoplasmonic Optical Microfluidics for Label-free Bioassays

Yir-Shyuan Wu
Luke P. Lee
Ming C. Wu
Steve Conolly
2009

Current cellular assays are limited to multi-well based cell culture samples, and the existing cellular protein detection methods are restricted to labeling the targeting molecules with fluorescent dyes or other reporters. Microfluidic cell culture technology can provide precise and physiologically relevant microenvironment control to improve the quality of cell based assays. Nanoplasmonic optical probes enable the label-free detection of cellular protein with high temporal and spatial resolution. The goal of this dissertation is to develop and integrate real-time label-free...

Microfluidic Microbial Fuel Cells for Microstructure Interrogations

Erika Parra
Liwei Lin
Carlos Fendandez-Pello
John D. Coates
2010

The breakdown of organic substances to retrieve energy is a naturally occurring process in nature. Catabolic microorganisms contain enzymes capable of accelerating the disintegration of simple sugars and alcohols to produce separated charge in the form of electrons and protons as byproducts that can be harvested extracellularly through an electrochemical cell to produce electrical energy directly. Bioelectrochemical energy is then an appealing green alternative to other power sources. However, a number of fundamental questions must be addressed if the technology is to become...

MEMS Resonant Strain Sensor Integration

David Myers
Albert P. Pisano
Liwei lin
Andrew Neureuther
2010

Despite commercial availability since the 1950’s, silicon strain sensors have not experienced the same success as other microdevices, such as accelerometers, pressure sensors, and inkjet heads. Strain sensors measure mechanical deformation and could be used in many structural components, improving safety, controls, and manufacturing tolerances. This thesis examines major strain sensing techniques and highlights both advantages and disadvantages of each. MEMS resonant strain gauges are identified to have superior performance over many traditional strain gauges in terms of sensitivity...