KINGSTON, R.I. -- May 13 2002 -- In order to improve the fuel efficiency of engines used to propel jets, rockets and space shuttles, the engines must be able to operate at higher and higher temperatures. But the current generation of sensors that assess the stresses on the engines cannot withstand these higher temperatures.

So the National Aeronautic and Space Administration (NASA) has given two major grants to a University of Rhode Island researcher to re-engineer the sensors so they can operate at temperatures over 2,000 degrees Fahrenheit.

"A jet engine is the most aggressive environment you can imagine," said Otto Gregory, professor of chemical engineering and co-director of the URI Sensors and Surface Technology Partnership. "The driving force behind jet engine improvements is efficiency. The hotter you can get the engine temperature, the more efficient the engine."

But as temperatures go up, it's necessary to make sure the materials can withstand the increased temperature. That's what Gregory is best at.

"We're good at high temperature materials improvements," said the Wakefield resident. "We can make the sensors more stable and improve the materials that the sensors are made of by changing the composition of the materials, applying heat treatments or changing coatings."

The sensors he's working on are flame spray strain gauges, tiny devices embedded in the materials used to make engine components. The gauges continually monitor the health of the engine and provide valuable feedback to the design engineers.

Gregory received $200,000 from NASA to make improvements that will extend

the life of the strain gauges and ensure they remain operational up to 2,400 F. For this project he is teaming with NASA, the Ohio Aerospace Institute's Propulsion Instrumentation Working Group (a consortium of jet engine manufacturers), and the leading supplier of the gauges.

In a related project, Gregory received $188,000 from NASA to make improvements to ceramic strain gauges, thin film gauges that are just 1/100th the thickness of a human hair. Ceramic strain gauges perform the same job as flame spray strain gauges, but they are used on more advanced materials.

Gregory is working on improving the heat tolerance of these gauges so they

can be used with ceramic matrix composites, experimental materials that can withstand temperatures of up to 3,000 F. NASA wants to use this material for the outside surfaces of the space shuttle and advanced aerospace planes, which must endure extreme heat when re-entering the atmosphere.

A third grant to combine the two projects is under consideration by NASA.

For Information: Otto Gregory 401-874-2085, Todd McLeish 401-874-7892