Wireless temperature microsensors integrated on bearings for health monitoring applications

This paper reports the performance of a wireless MEMS bimorph temperature sensor integrated on a bearing for component health monitoring applications. The sensor consists of a robust array of bimorphs consisting of gold and thermally-grown oxide operable to at least 300°C. Fabrication details are included, as well as the hermetic packaging information. Speed of actuation results from a high-speed camera is included showing the actuation time is less than 600 μs. Reliability testing of the bimorph array up to 400 million thermal cycles is also shown, after which the bimorphs still yield consistent behavior. Finally, dynamic testing is performed showing actual bearing temperature values at different speeds on a real-world helicopter bearing.