Cleveland-Three patents covering high-temperature, harsh-environment silicon carbide pressure sensors have been licensed by NASA's Glenn Research Center to Endevco Corporation, San Juan Capistrano, Calif.

The technologies include a packaging technique and chip fabrication methods that were developed by a team led by Dr. Robert Okojie at Glenn for use in aircraft engine combustion chambers. Silicon carbide (SiC) pressure sensors manufactured using these new processes can be used to improve testing of jet engines, in deep well drilling (where pressure and temperature increase as drilling depth increases), and in automobile combustion cylinders.

Silicon carbide is used for these new technologies, rather than the traditional silicon, which eliminates the need for cooling and enables operation in extreme temperatures. Currently, SiC-based pressure sensors built using these NASA technologies are able to operate for 130 hours at 600 degrees Celsius in air, making it durable and reliable for use for the first time in engine ground testing and short duration flight test instrumentation.

Glenn had used an Endevco silicon-based accelerometer in 2000 as a benchmark to validate Glenn's SiC accelerometer. Test results showed the NASA device operated as well as the Endevco benchmark device. However, NASA's SiC accelerometer had the added advantage of operating at much higher temperatures. This led to discussions between Endevco and Glenn about licensing opportunities to acquire Glenn's SiC pressure and accelerometer sensor fabrication and packaging technologies.

As NASA's development of these new methods progressed, Endevco became interested in licensing the technology. After numerous visits to Glenn to see the technology first hand, a license to three patents was signed last month. Okojie will continue to work with Endevco to assist in overcoming any outstanding technical issues with the licensed technologies.

According to Okojie, "Operation at high temperatures allows the SiC pressure sensors to be located in closer proximity to the sensed environment than conventional silicon based sensors, which must be isolated or protected in a water-cooled controlled environment. Placing the sensor closer to the harsh environment provides more reliable measurements. Additionally, its lighter weight due to absence of water-cooling plumbing makes the device less complex, relatively inexpensive and reduces tear-down cycle for engine maintenance. Its lightweight and reduced complexity leads to reduced engine weight for flight vehicles, hence improved fuel efficiency."

"Endevco is very pleased to be afforded the opportunity to work with NASA on technology that has application in such a wide variety of industries," said Endevco President Scott W. Silcock.

Endevco, a division of Endevco Corporation, a Meggitt group company, is a leading designer and manufacturer of dynamic instrumentation for vibration shock and pressure measurements. In 2006, the company expanded both the size and technical capabilities of its micro electro mechanical systems wafer fabrication facility in order to add controls and equipment to support advanced designs and enable high temperature and harsh-environment products.

"The transfer of technology to industry is a significant part of NASA's heritage and charter," said Kathleen Needham, chief of Glenn's Technology Transfer and Partnerships office. "We actively pick companies such as Endevco which have the ability and desire to bring NASA innovation to market."

Okojie's work is a combined effect of the Aviation Safety and Fundamental Aeronautics programs under NASA's Aeronautics Research Mission Directorate.

For more information on Glenn's silicon carbide electronics work, visit:

http://www.grc.nasa.gov/WWW/SiC

For more information on NASA's Aeronautics Research Mission Directorate, visit:

http://www.aeronautics.nasa.gov