||Thu 2009-Jan-29 11:48:56
||Wed 2013-Jan-30 09:00:09
||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.
Cutting out the comb fingers of electrostatic devices and replacing them with patterned electrodes
directly placed on the structural AlN layer has three distinct advantages. The devices have much
lower damping and can easily be operated at atmospheric pressure, the resonance frequencies can be
chosen more freely and adjusted for maximal noise rejection, and the shock and temperature
sensitivity is reduced. In this project, AlN accelerometers and gyroscopes are fabricated and tested
at extreme environmental conditions to explore the potential and limitations of AlN technology for
harsh environment inertial sensors.
|IAB Research Area
||Physical Sensors & Devices
||Fabian T. Goericke
||Albert P. Pisano