Recent Advances in Harsh Environment Acoustic Wave Sensors for Contemporary Applications

There is a significant need for wireless sensor systems capable of operation up to 1100 degrees C and beyond, in abrasive or corrosive harsh environments, in particular for the energy, steel, aerospace, oil and gas exploration industries. These environments and applications preclude the use of batteries and normally require wireless and multiple sensor interrogation. The University of Maine and Environetix Technologies have successfully responded to these needs by researching and developing surface acoustic wave (SAW) sensors based on the langasite family of crystals and co-deposited Pt/Rh/ZrO2 thin-film electrode technology. This paper reports on the recent achievements, which include: long term operation in furnace and technology validation in jet-engine static and rotating parts up to 53,000 g's; stable and repetitive wired and wireless responses of temperature sensors; multiple wireless sensor interrogation; and associated packaging (tests run in the 200 degrees C to 1000 degrees C range).