Authors: P. Nieva, N. McGruer, G. Adams
Affilation: University of Waterloo, Canada
Pages: 419 - 422
Keywords: MEMS, harsh environments, high-temperature sensors, sensing systems, optical MEMS, vibration sensor, pressure sensor, temperature sensor, interferometric techniques
This paper presents the development and experimental analysis of a new multi-purpose optical MEMS (micro-electro-mechanical system) sensor for harsh environments. The sensor can be used as a displacement sensor, accelerometer, seismometer, and with some minor modifications, for the simultaneous measurement of temperature and pressure. The small size of the sensor and its simple construction make it suitable for on-chip integration and ideal for harsh high-temperature applications.<br>MEMS for harsh environments are recognized as essential for reducing weight and volume, in strategic market sectors such as automotive, aerospace, turbomachinery, nuclear power and communications. An economical way to deal with higher temperatures is the use of materials exhibiting high temperature, chemical and mechanical stability as well as ease of integration with standard Silicon micromachining techniques. Furthermore, their integration with optical interferometric techniques permits the design of non-contact MEMS sensor systems suitable for localized precision measurements in harsh environments.<br>Two analytical models are presented to describe the operation of the optical MEMS sensor. A set of experimental results and the characterization for devices fabricated in SixNy are also described. Finally, the strong dependence of the sensor dynamic response on viscous damping is used to simulate its operation as a pressure-temperature sensor.