Blacksburg, VA (January 29, 2001) -- With the use of a new sensing device developed by Virginia Tech electrical engineers, energy intensive industries, including companies that specialize in transportation, power, glass, steel, and aluminum, should find that they can become less dependent on energy needs.
The use of these sensors should also reduce the emissions of pollutants.
Honeywell (formerly AlliedSignal), ABB, Howmet, and Corning are a few of the companies that have teamed with the Virginia Tech Photonics Laboratory (VTPL) and Oak Ridge National Laboratory to help commercialize the new sensing technology.
The sensors are designed for use in harsh environments, particularly where temperatures exceed 1500ºC, says Anbo Wang, director of the VTLP. For example, these extremely hot environments are the hosts to jet engines, power plants, and ceramic engines that might power the autos of the future.
By placing this sensing device in a jet engine, it could monitor sound-wave pressures, and warn the pilot that the engine is on the verge of shutting down. Or, this sensor in an auto engine could keep the vehicle operating at its most efficient temperature and pressure.
The industries VTPL has teamed with are logical choices. Honeywell is the leading producer of gas turbine engines and Corning is the leading manufacturer of optical fiber, cable, and photonic products for the telecommunications industry. ABB is the world's largest manufacturer of power generation equipment. Howmet leads the industries in the manufacturing of precision investment castings of aluminum, titanium, and superalloy for aircraft, turbine engines, and aerospace needs.
In the past, industry has primarily relied upon semiconductor pressure sensors that have several major drawbacks. These include a limited maximum operating temperature of 482ºC, poor reliability at high temperatures, severe sensitivity to temperature changes, and susceptibility to electromagnetic interference.
The Virginia Tech engineers produced the new sensor by combining several key technologies into a single sensor system. They focused on the advantages of each technology and significantly minimized the disadvantages.
In addition to the advantage of working in very high temperatures, the new sensor, called the self-calibrated interferometric/intensity based (SCIIB) sensor, is smaller in size, has higher resolution and accuracy, and a higher frequency response than its precursors. It is also immune to electromagnetic interference, has a strong resistance to chemical corrosion, is self-calibrating, and provides for an absolute measurement.
Another key to the success of the new sensor is one of the materials the engineers have chosen. They are using fibers made of single-crystal sapphire. According to Wang, "sapphire is an excellent material for the construction of harsh environment sensors due to its high melting point, excellent transparency, and well-documented resistance to corrosion." But the sapphire has been limited in its uses due to some technical constraints.
Based on VTPL's past success in developing the self-calibrating temperature and pressure sensors, the U.S. Department of Energy has just awarded $1.8 million to continue its work in this area. The Virginia Tech principal investigators on this program are Wang, Gary Pickrell, and Russell May, all from the Photonics Laboratory. In addition, the DOE awarded VTPL's partner, Oak Ridge National Laboratory, an additional $180,000 to collaborate on the project, and work towards the commercialization of these sensors. Oak Ridge maintains a internationally recognized sapphire material processing and fabrication facility.
The award will be divided over a three year period.
Some of the initiatives they will be working on, Wang says, include the use of a commercially available gold coated fiber with the SCIIB sensors. They will also investigate different polymer coatings that will withstand the higher temperatures.