The sensors detect when critical bearings are close to failing, as well as how long before they fail, letting maintenance personnel prevent costly breakdowns. The MEMS sensors are also small enough that they don’t interfere with the bearings. The sensors actually measure temperature, a good indicator of how well bearings are performing and when they can be expected to fail. Conventional bearing monitors track engine-oil temperature, an indirect method which yields less specific data. The sensors do not need batteries, which is a plus because batteries don’t perform well in hot environments. Instead power is supplied remotely through inductive coupling which uses coils of wire to generate current. The sensors send data out using telemetry.
Researchers at Purdue University working with the U.S. Air Force have developed wireless sensors strong enough to survive inside operating jet engines where temperatures can climb to 572°F.