Publications

Highly Scalable Silicon Photonic Switches Based on Waveguide Crossbar with Movable Waveguide Couplers

Sangyoon Han
Ming C. Wu
Richard S. Muller
Liwei Lin
2016
Fast opticalcircuitswitches (OCS) having a large number of ports can significantly enhance the performance and the efficiency of modern data centers by actively rearranging network patternsCommercially available optical switches typically operate with the use of moving mirror arrays. These switches can have port counts...

Fabrication and Characterization of Gecko-inspired Fibrillar Adhesive

Yongkwan Kim
Roya Maboudian
David B. Graves
Ali Javey
2014
Over the last decade, geckos remarkable ability to stick to and climb surfaces found in nature has motivated a wide range of scientific interest in engineering geckomimetic surface for various adhesive and high friction applications. The high adhesion and friction of its pads have been attributed to a complex array of hairy structures, which maximize surface area for van der Waals interaction between the toes and the counter...

Fabrication Of Ultra Thick Ferromagnetic Structures In Silicon

Debbie G. Jones
Albert P. Pisano
Seth Sanders
2004

A novel fabrication process has been developed to create ultra thick ferromagnetic structures in silicon. The structures are fabricated by electroforming NiFe into silicon templates patterned with deep reactive ion etching(DRIE). Thin films are deposited into photoresist molds for...

Fatigue of Polycrystilline Silicon in MEMS Devices

Angela S. Choy
Kyriakos Komvopoulos
Albert P. Pisano
Roger T. Howe
1999

A clear understanding of the mechanical properties of the structural materials used in MEMS devices is critical in the design and reliability analysis of these devices. However, it cannot be assumed that macroscale and microscale devices have the same behavior. Macroscale fatigue mathods cannot accurately predict the behavior of microscale devices because at microscale sizes, the structure size is on the same order of magnitude as the grain size of the material. Also, grain boundaries, environmental, and facrications effects, which are negligible on the macroscale, may be significant on...

Flexible Supercapacitors Based on Micro/Nanofibers

Caiwei Shen
Liwei Lin
Bryan McCloskey
Van Carey
2018
Flexible energy storage components are indispensable in the field of flexible electronicsSupercapacitors featuring high power density, fast charge/discharge rate, long cycle life, and safe operation are desirable devicesMicro/nanofiberbased electrode materials, fabrication processes, and device configurations are investigated towards flexible supercapacitors applications....

Fluidic Self-Assembly of Microfabricated Parts to Substrates Using Capillary Forces

Uthara Srinivasan
Roger T. Howe
Dorian Liepmann
Susan J. Muller
Jeffery A. Reimer
2001
In this work, we present a fluidic microassembly technique which uses capillary forces to self-assemble microparts onto a substrate. We have demonstrated this technique using microfabricated silicon parts and silicon and quartz substrates....

Evaporation-Driven Fast Crystallization of 3D Micro- and Nano-particle Assemblies via Micro Mechanical Systems

Sun Choi
Albert P. Pisano
Tarek I. Zohdi
Liwei Lin
Ming C. Wu
2012
Fast crystallization of solid-phase materials in liquid medium is a crucial prerequisite to achieve the aims of a number of applications for micro-, nanomanufacturing, bio-chemical sensing technology and fundamental colloidal scienceCorresponding mechanical systems for those applications are required to accommodate and take advantage of the virtue of multi-phase (liquid, gas, and solid phases) flow phenomenon to accomplish “crystallization...

Effects of Abrupt Changes in Microfluidic Geometry on Complex Biological Fluid Flows

Shelly Gulati
Dorian Liepmann
Susan J. Muller
Andrew J. Szeri
David Saloner
David Trebotich
2006
Direct measurement techniques are employed to quantify the kinematics of λDNA flows in three microfluidic components with abruptly changing geometries. Flow through these geometries subjects the fluid to large spatial gradients in velocity, leading to viscoelastic effects. The effects on DNA transport in microscale flows are significant because flow behavior may be influenced by elasticity of individual molecules, ...

Excimer Laser Annealing of Silicon Germanium for MEMS Applications

Carrie W. Low
Roger T. Howe
Tsu-Jae King
2004
Poly-SiGe is a promising material for modular integration of MEMS with electronics due to its low process thermal budget. Poly-SiGe can be deposited on top of standard CMOS electronics in a LPCVD reactor as a replacement of poly-Si as MEMS structure material. Deposition temperature at 450 °C along with 550 °C rapid thermal annealing can result good electrical and mechanical properties of the SiGe film. SiGe films deposited at lower temperature have degradations in mechanical properties, such as high ...

Electromagnetic Energy Harvester for Sensors on Overhead Power Distribution Lines

Zhiwei Wu
Liwei Lin
Richard M. White
Dennis Lieu
2020

The electric grid began its service over 100 years ago and accumulated many safety concerns regarding its infrastructure and nearby environment. The wireless sensor network has been deployed to monitor the condition of both the grid infrastructure and environment, and non-interrupted power sources with minimal maintenance has been an engineering challenge. Here, design of an inexpensive and durable electromagnetic energy harvester coupled with the magnetic field from the power line conductors for powering the wireless...