Physical Sensors & Devices

Research that includes:

  • Silicon MEMS actuators: comb, electro-thermal, and plastic deformation
  • Precision electronic sensing and measurements of capacitive, frequency, and coulombic MEMS variables
  • Structures and architectures for gyroscopes, accelerometers, micro strain gauges for direct application to rigid structures e.g., steel, and levitated MEMS

APP56/OO: Thermally-induced residual stresses in MEMS sensors

Bayram Orazov

In the course of eutectically bonding MEMS sensors to a substrate, residual thermal stresses can be induced in the sensor. These stresses have the potential to bias sensor signals, damage encapsulation and alter the operational range of the device. Using thermo- mechanical analyses, the goal of this work is to characterize the residual stresses and seek ways to ameliorate their effects on sensor packaging and operation.

Project end date: 08/14/07

BPN411: Tribology Test Chip for Contacting NEMS design

Donovan Lee

Tribological effects such as surface stiction and charging are not well understood. This research aims to develop test structures to study these phenomenon and give designers an understanding of the challenges we will face as NEMS devices scale. All-electronic metrology is proposed for this tribology chip, which is a departure from the traditional method of optical inspection for MEMS devices.

Project end date: 01/08/08

BPN365: MEMS Metal Gimbal: Design and Fabrication

Chris McCoy

The UC Berkeley MicroGimbal research project strives to parametrically optimize a 2DOF, torsional comb drive actuated gimbal platform that will support and position mm-scale imaging devices. Design parameters to be optimized in this feasibility study include but are not limited to: bandwidth, resonant frequency, payload capability, system mass, and degree of rotation. This two-student research team ultimately seeks to attain performance measures of low power consumption (P < 2W), large gimbal deflection (θ = +/- 30 deg.), high z-stiffness, high bandwidth, and high resonant...

BPN370: MEMS Metal Gimbal: Design and FEM

Ya-Mei Chen

The long range goal of this research is to analyze the a UC Berkeley designed MircoGimbal with a finite element method (FEM) simulator, ANSYS, to achieve design optimization. A fundamental design goal of the MicroGimbal is to maximize the rotation angle (current target is +/- 30 degrees) while minimizing the stress. TheorticallyTheoretically, it can be obtained by having cross section with low moment of inertia and long length . However, low moment of inertia and long length reduce the beams ability to support the payload in z-direction. Due to these competing phenomena, optimization...

BPN303: MEMS Biopolymer: Polymer Coated Cantilevers for Infrared Heat Sensing

Michael T. Mueller

The goal of this research is to use biomimetics to develop an uncooled, photomechanic infrared sensor formed from a cantilever bimorph. One side of the bimorph uses chitin (or potentially other polymers) in order to achieve a high thermal mismatch and maximize deflection. The objective is to maximize deflection for a given amount of incidient infrared radiation. Our design is inspired by the jewel beetle Melanophila acuminata, which has an IR-sensitive pit organ for the remote detection of forest fires, an evolutionary advantage that allows it to lay eggs in an area free of predators...

KSJP4: Microrobots

Sarah Bergbreiter

Our goal is to create a class of autonomous microrobots with a volume of less than 1cm3. We previously reported an autonomous micromachined silicon legged robot which took its first steps. The body of the robot was fabricated in a planarized silicon-on-insulator (SOI), two-layer polysilicon process and was 8 mm x 4 mm x 0.3 mm in size. The complete robot had two additional ICs, a solar cell and high voltage buffer chip along with a low-voltage CMOS chip for sequencing. However, due to the processing complexity and fragility of these robots, we are investigating new processing and...

BEB22: A Sub-mW Mode Matching Sigma-Delta Vibratory Gyroscope Readout Circuit

Chinwuba D. Ezekwe

We present the design and experimental results of a low-power, high-resolution gyroscope readout circuit. Several techniques are combined to enable an unprecedented level of power savings. Chief among them are automatic mode-matching, positive position sigma-delta force-feedback, and current integrator based position sensing. Mode-matching relaxes the electronic noise budget of the front-end amplifier by the sense Q, resulting in a proportional reduction in front-end power dissipation. Unfortunately, it also results in an extremely narrow open-loop sensor bandwidth owing to the high...

DL13: Multidirectional Force and Torque Sensor for Insect Flight Research

Mansoor Nasir

In order to understand the unsteady aerodynamics of insect flight, a sensor has been fabricated that measures the small multidirectional forces generated by fruit flies during tethered flight while simultaneously supporting it inside a LED flight simulator arena. This sensor will provide quantitative data that will help to better understand sensorimotor mechanisms of flight control in flying insects.

Project end date: 01/29/08

BPN443: Ultra-Smooth Conducting Parallel Plates with Nanoscale Separation for Single Molecule Sensing and Investigation of Casimir Force

Aaron M. Katzenmeyer

We constructed a pair of parallel conducting metal (Ag) plates separated by patterned molecular monolayers at the corners of the plates. A special metal deposition process was developed to ensure atomic scale flatness in the conducting plates. The separation between the plates can be controllably varied between several angstroms and tens of nanometers by varying the length of the molecules and/or employing conventional substrate processing techniques. The structure is an efficient sensor for detecting single molecules via surface enhanced Raman spectroscopy (SERS). The unique...

APP78: SiC TAPS: Capacitive Sensors Design and Fabrication

Babak Jamshidi

The main objective of the project is to design and fabricate capacitive sensors capable of performing under harsh environments. The main focus of the project is to develop a strain gauge which measures strain at micron scale to improve the operational characteristics of its substrates in applications such as automotive and aerospace. Contrary to traditional and commercial strain gauges, temperature and aging have a relatively small influence on the sensitivity and precision of this type of sensor. Three major goals have been set for the course of research. The most prior goal is to...