Liwei Lin (Advisor)

Research Advised by Professor Liwei Lin

Lin Group:  List of Projects | List of Researchers

Thermal Ground Plane for Chip-Level Electronics Cooling

Hongyun So
Albert P. Pisano
Liwei Lin
Tsu-Jae King Liu
2014

The three-dimensional thermal ground plane was developed in response to the needs of high-power density electronics applications in which heat must be removed as close to the chip surface as possible. The novel design for this planar cooling device was proposed with three key innovations in the evaporator, wick, and reservoir layer, which provided enhanced and reliable cooling performance without wick dryout and back flows. For the evaporator and reservoir layer, a combination of a tapered channel and a triple-spike microstructure was designed to break up the pinned meniscus at the...

Templated Dry Printing of Conductive Metal Nanoparticles

David Rolfe
Albert P. Pisano
Liwei Lin
Amy Herr
2015

Printed electronics can lower the cost and increase the ubiquity of electrical components such as batteries, sensors, and telemetry systems. Unfortunately, the advance of printed electronics has been held back by the limited minimum resolution, aspect ratio, and feature fidelity of present printing techniques such as gravure, screen printing and inkjet printing. Templated dry printing offers a solution to these problems by patterning nanoparticle inks into templates before drying.

This dissertation shows advancements in two varieties of templated dry nanoprinting...

Carbon Nanotube Films for Energy Storage Applications

Alina Kozinda
Liwei Lin
Roya Maboudian
Dorian Liepmann
2014

With the rising demands for small, lightweight, and long-lasting portable electronics, the need for energy storage devices with both large power and large eneergy densities become vitally important. From their usage in hybrid electric vehicles to wearable electronics, supercapacitors, and rechargeable batteries have been the focus of many previous works. Electrode materials with large specific surface areas can enhance the charning speed and total amount of stored energy. To this end, vertically self-aligned conductivities as well as high mechanical stregth and large specific surface areas...

Droplet-Based Microfluidic Systems: Finger-Powered Pumps, Reactors and Magnetic Capsules

Kosuke Iwai
Liwei Lin
Albert P. Pisano
Luke P. Lee
2014

The combination of microfabrication and microfluidics has enabled a variety of opportunities in making new tools for biological and diagnostic applications. For example, microdroplets-based systems have attracted lots of attentions in recent years due to potential advantages in controlled environments with fast reaction time, high-throughput and low noises. This work presents a number of advanced microfluidic systems in process, control and manipulation of microdroplets, including finger-powered pumps to generate microdroplets, continuous-flow rupture reactors for the rupture and...

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,...

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....

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....