Researchers in the Center for Photonics Technology are developing a new process to manufacture robust pressure sensors that can operate in temperatures up to 1500 degrees Celsius and in extremely harsh environments. Current pressure sensing technology is limited to about 600 degrees Celsius.
"This technology could be used to monitor real-time pressure fluctuations in high temperature furnaces, jet engines, combustion engines, chemical reactions, or corrosive environments," said Bradley Fellow Evan Lally, who is on the development team.
The all-sapphire pressure sensor is constructed through a novel combination of etching and bonding techniques applied to single-crystal sapphire components. The result is a Fabry-Perot cavity with a thin diaphragm, which flexes in response to ambient pressure changes. The sensor can be made smaller than 1 cm. wide.
Sapphire is an extremely hard, corrosion resistant crystal with a melting point over 2000 degrees Celsius, which makes it an ideal material for high-temperature, harsh environments, he explained. It is immune to electromagnetic interference, and because sapphire is a good insulator, the sensor could be used in applications where electronic pressure sensors could cause an ignition hazard.