Description: There is an acute need for robust sensors and sensor systems capable of operation in harsh environments. In particular, high temperature passive wireless surface acoustic wave (SAW) sensors are highly desirable for improving safety and efficiency in aviation and space vehicles. Such sensors are used for the detection of fuel leaks in engines, fire in its initial stages, fuel flow modulation and control and monitoring, and in-flight NDE and diagnostics of vehicles. In this project, we will 1) develop a relatively new crystal material suitable for high-temperature SAWs; 2) design SAW sensors and investigate extremely high temperature operation (up to 1000oC) of the SAW sensor embodiments; 3) Integrate the SAW and antenna onto the wafer such that there are no external connections. This will form a fully integrated sensor antenna device without any external bonds or soldering. Phase I will include substantial materials development and characterization for uniformity and repeatability in SAWs. Prototype SAW designs will be developed and high-temperature characteristics evaluated. Phase II will develop a fully integrated sensor antenna and upscale the crystal growth for 3-4in SAW wafers. Probability for Phase III commercialization of both the wireless SAW sensors and SAW wafers is high.

Benefits: Broader applications: SAW filters for cell phones; touchscreen displays; RFIDs; microfluidic actuation (pumping, mixing, jetting); fixed delay lines for radar systems, oscillators, path lengths equalizers; SAW delay line tunable VHF/UHF oscillators for mobile radio; bandpass filters in TV video game systems; linear and nonlinear frequency modulation chirp filters for radar; adaptive filters for spread-spectrum communications; acousto-optic spectrum analyzers; fixed frequency oscillators with high-short term stability; low-loss bandpass filters applications; plate convolers for fixed- and variable-code detection in radar, electronic counter-measures, air traffic control and handling systems; and many others.

Wireless LGT SAW sensors and sensor systems capable of operation in harsh environments will be of immediate use to NASA. Among others, such high-temperature SAW sensors can be used for the detection of fuel leaks in engines, fire in its initial stages, fuel flow modulation and control for engine efficiency and enhanced maneuverability, monitoring and in-flight NDE, and diagnostics of vehicles. Overall they will greatly improve safety and efficiency in aviation and space vehicles.