Abstract: Harsh environmental conditions, including extremes of pressure, temperature, vibration, shock, radiation, etc., pose a great challenge for conventional sensing devices. Accurate monitoring of pressure and temperature in such extreme environments is critical to several modern industrial segments such as the automotive, aerospace, gas turbine, nuclear power, and gas and oil exploration. However, most existing sensing elements on the market could not survive in such harsh environments.

Langasite (La3Ga5SiO14), or LGS, is a promising new piezoelectric material that combines many of the advantages of quartz, barium titanate and lithium niobate in having high electromechanical coupling and good frequency-temperature characteristics. One of the most important features of langasite is that it will not undergo any phase transitions up to its melting temperature of 1473°C, which makes it very promising for applications in high temperature environments. This talk will present several key issues on the design of langasite/quartz-based BAW (Bulk Acoustic Wave) resonant pressure/temperature sensors and Gas sensors. The discussion includes the introduction of the new piezoelectric material, design principle and theoretical analysis for a pressure/temperature sensor and the experiment validation. The author’s other work on sensors such as viscosity, gas, current sensors and ultrasonic data communications will be reviewed as well.

Speaker: Dr. Zhang is an Associate Professor of the Department of Mechanical and Energy Engineering at the University of North Texas (Denton, TX). His research interests include innovative sensing (BAWand SAW) devices in harsh environments, MEMS gas sensors, structural health monitoring and nondestructive test methods. Dr. Zhang has been the PI or a co-PI of $4.7M grants (his own share $2.0 M) from a variety of federal funding agencies such as USDA, NSF, DOE, ARO, DOD, and US Army NATIC. He has published more than 50 journal and conference papers. He received his B.S. in Engineering Mechanics from Hunan University, China in 1997, hisM.S. degree in Solid Mechanics from Northwestern Polytechnical University, Xian, China, in 2001, and his Ph.D. degree in Engineering Mechanics from University of Nebraska, Lincoln in 2007. He was a postdoctoral researcher in the Department of Material Science and Engineering in the Ohio State University before joining in University of North Texas in 2008.

Speaker(s): Dr. Haifeng Zhang,

Location:
Room: Crick Rm (2008)
Bldg: BSF
3300 Stevens Drive
Richland, Washington
99354