Silicon-Micromachined Absolute Pressure Sensor for Deep, Underwater Applications

During the Phase I program, the development team consisting of Fiber & Sensor Technologies, Inc. (F&S) and Pressure Systems, Inc. (PSI) proposes to investigate the feasibility of both fiber optic-based and electrical-based silicon micromachined absolute pressure sensors. Optical fiber sensor technology possesses a number of practical advantages over traditional electrical-based instrumentation, including very high dynamic range, immunity to electromagnetic interference, the ability to be operated remotely in harsh environments otherwise unsuitable for traditional sensing techniques. F&S has already developed a commercially-available absolute displacement sensor and, during previous and on-going SBIR and non-SBIR programs, has developed prototypes of silicon micromachined differential pressure sensors for monitoring pressure on aircraft and differential silicon-micromachined acoustic microphones for wind tunnel test applications. PSI has developed differential pressure sensors based on silicon- micromachining technology that are submersible in liquid environments at depths up to 1000 feet. The development of silicon micromachined absolute pressure sensors would eliminate liquid backfill techniques currently required to provide a reference pressure for differential type pressure sensors.