Publications

Integrated Microfluidic Molecular Diagnostics for Point-of-Care

Charlie (Erh-Chia) Yeh
Luke P. Lee
Ming C. Wu
2015

Ideal point-of-care medical diagnostic devices are low cost assays capable of performing quantitative on-site rapid testing with high sensitivity and minimal manual steps.

Current mainstream assays have several key limitations. Take, for instance, the common lateral flow assay—e.g. the pregnancy dipstick test. Such assays produce rapid results at low cost; however, they are mostly qualitative tests yielding only positive/negative results rather than quantitative figures. Other standard immunosorbant assays such as ELISA yield quantitative results but require...

High Energy Density Metal Oxide and Conducting Polymer Supercapacitors

Roseanne Warren
Liwei Lin
Albert P. Pisano
Ali Javey
2015

Supercapacitors are electrochemical energy storage devices characterized by rapid charge- discharge speeds, high power densities, and long cycle lifetimes compared to batteries.1,2 Supercapacitors have many promising applications as energy storage devices in electric vehicles, renewable energy systems, grid energy management, as well as stationary and portable electronics.2 A current limitation of supercapacitors is their low energy density compared to batteries, which hinders their application as stand-alone energy storage systems...

Magnetic Nano Particles and Thin Films for High Frequency Micro Inductors

Kisik Koh
Liwei Lin
Dennis K. Lieu
Ana C. Arias
2015

The size and performance of integrated circuits have been following Moore’s law to continuously shrink and progress over the past decades while on-chip inductors have seen little advancements. This work proposes several unique approaches in the integrated magnetic cores for high frequency micro inductor developments, including: (1) spherical-shape, anti-oxidizing magnetic nanoparticle composites; (2) sputtered magnetic thin films with magnetization-induced anisotropy; and (3) rectangular-shape magnetic particles with geometry-induced anisotropy. Theoretical and simulation studies...

Electron Devices Based on Transition Metal Dichalcogenides

Mahmut Tosun
Ali Javey
Junqiao Wu
Liwei Lin
2016

Integrated circuits consists of building blocks called transistors. A transistor is a switch that enables logic operations to perform computing. Since the invention of the first integrated circuit, transistors have been scaled down in their dimensions to increase the density of transistors per unit area to enable more functionality. Transistor scaling is continued by introducing novel device structures and materials at each technology node. Due to the challenges such as short channel effects and the power consumption issues, novel materials are investigated as a candidate for next...

Integrated 4H-Silicon Carbide Diodes and Bridge Circuits for Harsh Environment Applications

Shiqian Shao
Albert P. Pisano
Liwei Lin
Tsu-Jae King Liu
Jie Yao
2016

High temperature electronics, micro-electro-mechanical systems (MEMS) and sensors that are able to operate between 300°C to 600°C have broad applications in harsh environments such as oil/gas exploration, geothermal development, industrial manufacturing processes, and space exploration. 4H-silicon carbide (SiC) is a good material for harsh environment applications because of its wide bandgap, high carrier mobilities, excellent thermal and chemical stabilities, and high breakdown electric field strength. Several 4H-SiC devices and integrated circuits have been studied in this work,...

Neural Dust: Ultrasonic Biological Interface

Dongjin Seo
Michel M. Maharbiz
Elad Alon
John Ngai
2016

A seamless, high density, chronic interface to the nervous system is essential to enable clinically relevant applications such as electroceuticals or brain-machine interfaces (BMI). Currently, a major hurdle in neurotechnology is the lack of an implantable neural interface system that remains viable for a patient’s lifetime due to the development of biological response near the implant. Recently, mm-scale implantable electromagnetics (EM) based wireless neural interfaces have been demonstrated in an effort to extend system longevity, but the implant size scaling (and therefore...

Growth and Characterization of Silicon Carbide Thin Films and Nanowires

Lunet Luna
Roya Maboudian
Carlo Carraro
Jeffrey Reimer
Liwei Lin
2016

Silicon carbide (SiC) based electronics and sensors hold promise for pushing past the limits of current technology to achieve small, durable devices that can function in high-temperature, high- voltage, corrosive, and biological environments. SiC is an ideal material for such conditions due to its high mechanical strength, excellent chemical stability, and its biocompatibility. Consequently, SiC thin films and nanowires have attracted interest in applications such as micro- and nano-electromechanical systems, biological sensors, field emission cathodes, and energy storage devices....

Deconstruct, Imagine, Build: Bringing Advanced Manufacturing to the Maker Community

Joanne Lo
Eric Paulos
Bjorn Hartmann
Paul Wright
2016

Physical prototypes serve as a common starting point for the process of innovation, improvement of an existing product, and experimentation of new interactions. As the shapes, forms, and functions of the electronic landscape rapidly evolve, fabrication and prototyping methods need to keep up with the changing needs as well. This dissertation contributes concepts and techniques that answer two research questions:

1. What type of prototyping processes and tools could support the rapidly evolving field of interactive technology?

2. How can these...

Environmental Gas Sensing With High Surface Area Nanomaterials on a Low-power Microfabricated Heater Platform

Anna Harley-Trochimczyk
Roya Maboudian
David B. Graves
Liwei Lin
2016

Gas sensors can provide information about the presence of dangerous gases in industrial and residential sites, allowing for improved environmental protection and human health and safety. In order to enable ubiquitous wireless monitoring of combustible and toxic gases, sensor elements with low power consumption are required. Two common types of gas sensors, namely calorimetric and conductometric sensors, rely on heated sensor elements to activate the appropriate reactions with the gas of interest, resulting in high power requirements to maintain the necessary operating temperatures....

Microfluidic Analysis of Vertebrate Red Blood Cell Characteristics

Kathryn Fink
Dorian Liepmann
Luke P. Lee
2016

Continuous multidisciplinary advancements in medicine, science and engineering have led to the rise of biomedical microfluidic devices for clinical diagnoses, laboratory research for modeling and screening of drugs or disease states, and implantable organs such as artificial kidneys. Blood is often the biological fluid of choice for these purposes. However, unique hemodynamic properties observed only in microscale channels complicate experimental repeatability and reliability.

For vessels with 10-300μm diameters, red blood cell properties such as deformability...