241-UF. High Temperature, Optical Sapphire Pressure Sensors for Hypersonic Vehicles

Team

Project Description

Orbital commercial space vehicles require high-temperature sensors (~1000°C/1600°F) or various phases of flight (e.g, hypersonic flight, high speed reentry) or to monitor system and subsystem performance (e.g., for gas turbines or scramjets). Current commercial sensors are only capable of up to ~300°C/600°F.

Project Outcomes

• Design a sapphire optical lever microphone via multiphysics analytical modeling
• Develop thermocompression fabrication methods for the formation of devices with moving parts out of sapphire and platinum
• Development of techniques for ultrafast laser micromachining of sapphire for sensor and packaging fabrication
• Fabrication and packaging of pressure sensors optimized for low-noise and high-sensitivity while possessing minimal drift associated with changes in relative humidity, temperature, etc.
• Characterization of sensors in a simulated, high temperature, pressurized laboratory environment
• Implementation in a hypersonic flow facility (such as Arnold Engineering Development Center, etc.) and/or a gas turbine (such as the Capstone C60 microturbine at the University of Florida, etc.)

Summary of Output

Design a fiber optic lever pressure sensor with a remote photo-diode optical readout. The microphone is composed of a compliant, platinum coated, sapphire diaphragm bonded over a cavity containing a single optical fiber. The diaphragm deflection is detected via intensity modulation due to the motion of the reflective platinum coated sapphire diaphragm. The optical signal is routed via the high temperature sapphire fiber to a remote photo-diode allowing for insulation of the electronics from the harsh environment.