A multisensor employing an ultrasonic Lamb-wave oscillator

Abstract

Initial experimental, analytical, and numerical evaluations of a microsensor that uses ultrasonic Lamb waves propagating in a thin plate supported by a silicon die are presented. Changes of oscillator frequency indicate magnitudes of the variables sensed. Because it is sensitive to many measurands, the device could operate as a microphone, biosensor, chemical vapor or gas detector, scale, pressure sensor, densitometer, radiometer, or thermometer. Because it is based on the use of Lamb waves, the sensor has selective response and sensitive operation in the low-megahertz frequency range in vacuum, in a gas, or while immersed in a liquid. >