A MEMS optical moiré shear stress sensor for harsh environment applications

Abstract

This paper describes the development of a shear stress sensor for use in harsh environments as well as experimental characterization of the sensor system. The microelectromechanical systems (MEMS) sensor utilizes optical moiré transduction of a floating element structure created using a silicon-on-Pyrex fabrication process. Interrogation of the amplified moiré displacement is achieved via a four-channel fiber optic array. The sensor and array are packaged in a robust housing to enable installation in multiple test facilities. Mean flow characterization of the system demonstrates a sensitivity of 13.4 mrad/Pa, minimum detectable shear stress of 54 mPa at 1 kHz with a 1 Hz bin, and experimentally verified dynamic range of 39.2 dB.