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

BPN481: HEaTS: Aluminum Nitride Technology for Inertial Sensors

Gabriele Vigevani

The goal of this work is to design and fabricate inertial sensors based on c-axis oriented AlN polycrystalline thin films. AlN is a post-CMOS compatible piezoelectric material widely used for acoustic resonators, such Bulk Acoustic Wave (BAW) and Lamb Wave Resonators (LWR). In this work we develop the design techniques necessary to obtain inertial sensors with AlN thin film technology. Being able to use AlN as structural material for both acoustic wave resonator and sensing elements is key to achieve the three level integration of RF-MEMS components, sensing elements and CMOS in the...

BPN537: Liquid Bearing Micromotors

Brian Yoxall
Mei-Lin Chan

This project aims to develop a free, untethered micro-rotary platform based on liquid bearing support. The liquid bearing is essentially a small volume of fluid confined between the rotor and stator by patterned Teflon surface coatings. These bearings have the distinct advantage of being minimally affected by wear and capable of supporting both static and shock loads with reduced mechanical vibrations. The rotor is actuated through three phase electrostatic driving by etching notches in the perimeter of the silicon rotor and depositing metal electrodes onto the glass stator substrate...

BPN641: InAs XOI Gas Sensor

Junghyo Nah

The objective of InAs XOI gas sensor project is twofold. First, the role of size effect on sensor performance will be systematically investigated. Our XOI device structure provides a unique platform to perform this study since we can precisely control material thicknesses and transfer them on a SiO2/Si substrate. Based on this study, we will determine physical role of size effect on sensor performance. This result will be also essential to determine an optimum NR thickness for gas sensors. Secondly, we will implement multiple gas detection sensor modules on a single chip by...

APP96: HEaTS Sensors for Extreme Harsh Environments

Debbie Senesky

The goal of the Harsh Environment and Telemetry Systems (HEaTS) program is to deliver a wireless sensor module with MEMS-based silicon carbide (SiC)sensors integrated with SiC interface circuits for extreme harsh environment applications.

Project end date: 08/13/12

BPN388: Micro Autonomous Air Vehicles

Ankur Mehta

This project considers the design and implementation of a guidance and control system for small scale autonomous air vehicles, in particular helicopters. A two gram inertial navigation unit has been designed and built for this purpose, using a three axis angular rate sensor and three axis accelerometer for trajectory measurements, along with a microprocessor and 2.4 GHz 802.15.4 radio. A smart IR camera is used to determine localization information. This extremely low mass wireless enabled sensor mote can be used as a platform for two-fist sized autonomous vehicles, and this system...

BPN539: Micromechanically-Enhanced Magnetoresistive Sensors

Gerardo Jaramillo
Andre Guedes

Magnetoresistive (MR) sensors are highly sensitive magnetic field sensors but suffer from large 1/f noise. We have developed a new approach for reducing the 1/f noise in MR sensors by using a MEMS resonator to mechanically modulate the magnetic field signal to a high frequency, where the 1/f noise vanishes. This mechanism improves the MR element sensitivity by 2-3 orders of magnitude in the low frequency sensing range. A fully integrated fabrication process was developed, where the MR sensor is fabricated first on the surface of a SOI wafer and the MEMS actuators are fabricated last...

BPN656: Airborne Particulate Monitoring Using a Micromechanical Electrometer

Gerardo Jaramillo

Environmental air quality is monitored by accurately sizing and quantifying nanometer-sized aerosol particles present in the atmosphere. One method of detection electrically charges the particles and then feeds a stream of charged particles into a Faraday cup electrometer. We present the first results of a MEMS based electrometer for the detection of small currents from ionized particles in a particle detection system.

Project end date: 08/12/13

BPN499: HEaTS: Aluminum Nitride Inertial Sensors for Harsh Environments

Fabian T. Goericke

Aluminum nitride (AlN) is a promising candidate for an emerging field of sensors that is inaccessible for electrostatic devices. Harsh environment conditions, such as temperatures above 500 deg C, high pressures, or reactive media are detrimental to today's MEMS sensors. Devices based on the inert, high melting point material AlN however can withstand these and even harsher conditions. The piezoelectric properties of the material are preserved to very high temperatures (up to 1000 deg C) and can be used for sensing in accelerometers and both sensing and actuating in gyroscopes....

BPN642: 10 MHz Optical Phased Array Metrology and Control

Mischa Megens

Very fast optical beam steering and wave front correction can be achieved by employing phased arrays of lightweight High Contrast Grating (HCG) MEMS mirror etalons. The etalons provide a large phase shift for a small displacement, 100x more than traditional reflective mirror elements. Operating such etalon arrays requires exquisite control of the MEMS mirror displacements. Our aim is to use in-situ stroboscopic interferometric imaging of the etalons to ensure phase accuracy and combat long term-drift, while employing feed-forward electrical input shaping to achieve fast settling time...

BPN485: Ultrasonic Gesture Recognition on a Chip

Richard J. Przybyla
Hao-Yen Tang

Optical 3D imagers for gesture recognition, such as Microsoft Kinect, suffer from large size and high power consumption. Their performance depends on ambient illumination and they generally cannot operate in sunlight. These factors have prevented widespread adoption of gesture interfaces in energy- and volume-limited environments such as tablets and smartphones. Gesture recognition using sound is an attractive candidate to overcome these difficulties because of the potential for chip-scale solution size, low power consumption, and ambient light insensitivity. Our research focuses on...