Roya Maboudian (Advisor)

Research Advised by Professor Roya Maboudian

RM8: Stiction in MEMS

Brian Bush

Electrostatic forces, due to trapped charge or applied voltage, can lead to unwanted adhesion in MEMS devices. We wish to use various techniques, including Electronic Force Microscopy (EFM) and Cantilever Beam Arrays (CBA), to characterize the effect of surface modifications on the electrical properties of MEMS components and to better understand the forces that cause stiction. This knowledge will enable one to develop novel surface modifications or self-assembling monolayers that are specifically designed to combat stiction due to electronic forces.

Project end date:...

RM5/RTH: Silicon carbide process development and characterization for harsh-environment sensors

Jingchun Zhang
Carlo Carraro

Silicon carbide (SiC) is a wide band gap semiconductor with extraordinary properties and has attracted considerable attention for high temperature electronics. Recently, this material is being pursued for microelectromechanical systems (MEMS) applications in harsh environments. The goal of this project is to develop a series of SiC-based sensors and to characterize them for harsh environments. In order to achieve thisgoal, a series of microfabrication technologies including low-temperature CVD, reactive ion etching, and metalization of poly-SiC films need to be developed. In addition...

RTH42: Nanowire-Coupled Resonators

Noel Arellano

We have developed fabrication processes to create top down nanowire coupled resonators. The critical dimensions were defined using a combination of iline lithography, photoresist ashing techniques and focused ion beam trimming. Nanowires are used as mechanical elements to demonstrate low velocity and maximum velocity coupling. We have also demonstrated an bottom up/ top down integrated fabrication process. Features for the top down segment of the fabrication process are aligned to (111) flat on a (110) SOI wafer. A gold based galvanic displacement method selectively deposits catalyst...

RM7/RTH: Dedicated SiC MEMS LPCVD Reactor for Access through the DARPA MEMS Exchange Program

Christopher S. Roper

This project seeks to make Silicon Carbide thin films available to MEMS researchers and designers. A process developed in the Maboudian Lab at UC Berkeley which currently accommodates 2-inch wafers will be scaled up to accommodate 4- and 6-inch wafers. High quality poly-crystalline 3C-SiC films deposited at reasonable growth rates, with controlled residual stress, controlled strain gradient, controlled resistivity, and high uniformity will be sought. Once films with high overall quality and repeatability are grown the process will be released to the MEMS community.


BPN582: HEaTS: Structurally Multifunctional Actuation and Readout Techniques for MEMS (SMART MEMS)

Kamran Shavezipur
Jamie Young

The goal of this project is to develop multifunctional sensors for harsh environment where using one device different physical parameters can be measured. The main focus for the current phase is on a multifunctional temperature-pressure sensor that simultaneously measures both pressure and temperature using a smart structure and capacitive readout.

Project end date: 01/26/12

BPN763: Surface Acoustic Wave-Based Sensors for Harsh Environment Applications

Shuo Chen

Sensing in harsh environment, especially high temperature environment, is drawing more attention, with potential applications in energy sector. The motivations are that enhanced (pressure, temperature, chemical) sensing will allow more efficient operation, enabling condition- based monitoring and reducing unwanted emission. State-of-the-art sensing technology remains limited, either not capable of long-term online monitoring under high temperature due to materials failure or, occupying too much space. We propose to adapt MEMS fabrication process and concepts to our proposed research...

BPN424: Silicon Carbide Nanomaterials for Harsh Environment Applications

Lunet E. Luna

Silicon Carbide (SiC) is a material of interest to fabricate sensors and actuators able to operate in harsh environments. Particularly, its mechanical and electrical stability and its chemical inertness make SiC well suited for designing devices capable of operation in high temperature and corrosive environments. Harsh-environment stable metallization remains one of the key challenges with SiC technology. We are developing novel metallization schemes, utilizing solid-state graphitization, to improve the long-term reliability of Pt/Ti/poly-SiC contacts in high temperature environments...

BPN783: Low-Power Conductometric Soot Sensor with Fast Self-Regeneration

Ameya Rao

We are designing a conductometric soot sensor that measures the change in conductance resulting from soot deposition onto the sensor. Although previous work has been done on conductometric soot sensing, current sensors are power intensive (5-30 W) and slow (60-170 s between sensing cycles) due to their large size, ineffective thermal insulation, and the high currents required for soot combustion (when self-regenerating). We propose to use MEMS fabrication methods to develop a miniaturized conductometric soot sensor with a built-in polysilicon microheater for self-regeneration, whose...

BPN797: Synthesis and Friction Characteristics of Gecko-Inspired Adhesives

Hai Liu
JuKyung Choi
Gina Zaghi

Geckos have a remarkable ability to stick to and climb almost any type of surface using micro- and nanoscale foot- hairs, which allow conformal contact against any counter-surface and thus, maximize the interfacial interaction. With the goal of mimicking the high adhesion and friction capability of geckos, we have fabricated ordered polymeric nano-fiber arrays of various soft and hard polymers, including low-density polyethylene and cyclic olefin polymers. In order to provide a useful reference for optimum high performance conditions, the effects of fiber geometry (diameter and...

BPN819: Hybrid Porous Nanowire Arrays for High Energy Supercapacitor

Sinem Ortaboy

Recently, silicon-based supercapacitors have received considerable attention for application in mobile and remote sensing platforms due to their unique properties such as high surface area, low cost, long lifetimes, and excellent charge–discharge capability. These promising energy storage devices store more energy than conventional dielectric capacitors and deliver higher power with longer cycle life than available battery technologies. Recent studies in the field of supercapacitors have focused on the realization of hybrid materials to further improve the energy density of...