High Temperature Metal RubberTM Sensors For Skin Friction Measurements

The Air Force Phase I STTR program would develop and demonstrate high temperature version of ‘sensor skins’ capable of multi-axis flow characterization on air breathing hypersonic engines. This would build upon NanoSonic’s successful demonstration of Metal Rubber™ transducer materials for the measurement of flow-induced skin friction and pressure at low temperatures and transonic and supersonic flow regimes. During this program, NanoSonic would work cooperatively with Virginia Tech to develop an improved mechanical and electrical model of high temperature version skin friction sensor performance that will allow quantitative optimization of material properties and suggest optimal methods for sensor attachment and use for hypersonic engine applications. We will perform synthesis of sensor skin materials with optimized transduction, hysteresis and environmental properties, specifically for high Reynold’s number flow and also varying temperature use. We will fabricate patterned two-dimensional sensor arrays and internal electronics using optimized materials. Calibration of sensor elements will be conducted in both instrumented water and air flow systems at NanoSonic, Virginia Tech and Air Force center. NanoSonic and Virginia Tech will perform complete analysis of sensor cross-sensitivities and noise sources to allow optimization of signal-to-noise ratio and practical sensor sensitivity. Support electronics will be developed to acquire, multiplex, store and process raw sensor array data. NanoSonic and Virginia Tech will also experimentally validate sensor array performance through extended water and wind tunnel evaluation, and possible flight testing with Lockheed Martin Aeronautics, and produce a first-generation high temperature skin friction sensor array and data acquisition electronics system for sale. BENEFIT: The anticipated initial market of the high temperature version of Metal Rubber™ sensor skin arrays is for wind tunnel testing and hypersonic engine testing. An appreciation of the instrumentation issues would allow improvements in sensor materials, electronics and packaging, and potentially allow the transition of related products to operational vehicles. The commercialization potential of the Metal Rubber™ technology developed through this Air Force STTR program lies in four areas, namely 1) High Temperature Metal Rubber™ sensor skin arrays for the measurement of skin friction, 2) Broader sensor skin arrays for the measurement of pressure, 3) Single-element air or water flow sensors, and 4) Metal Rubber™ material itself. Such broader commercial sensor opportunities would be considered.