High-Temperature Aeropropulsion Sensors Using Sapphire Microoptomechanical Systems

Robust sensors that can survive the high-temperature environment of gas turbine engine hot sections are critically needed for test and validation of advanced engine designs. Sensors based on semiconductors, silicon carbide, or silica optical fibers are unlikely to satisfy those needs in the near future, due to high temperatures and corrosion in the engine environment. While sensors made of sapphire optical fibers can withstand the environmental extremes, difficulties in fabricating sapphire sensors have thus far limited demonstrations of sapphire sensors to laboratory environments. Prime Photonics, teaming with Virginia Tech and Oak Ridge National Laboratory, proposes to develop technology to enable manufacturing of microoptomechanical sensors (MOMS) using single-crystal sapphire materials. In particular, methods for micromachining, bonding, and writing planar waveguides in sapphire will be investigated and evaluated. Designs of pressure, temperature, strain, and flow that leverage the new technology will be derived, for fabrication and test in Phase II. Use of MOMS technology for construction of sapphire engine sensors is expected to lower manufacturing costs, improve sensor repeatability, and reduce calibration requirements.