Proximity Measurement of Pressure and Temperature

Inexpensive, high-performance, optically coupled temperature and strain gauges based on a combination of advanced optoelectronic and microelectromechanical concepts have been proposed. The sensors would contain vibrating beams with submillimeter dimensions, made primarily of silicon by microfabrication techniques. The beams would be designed so that (1) their resonance frequencies would vary with strain and temperature, respectively, and (2) their vibrations would be both excited and measured by use of light. The sensors would be impervious to mechanical shocks, would have masses in the microgram range, and would consume only femtowatts of power. Unlike electrically coupled sensors, the proposed sensors would be immune to (and would not generate) electromagnetic interference at suboptical frequencies.