A microelectromechanical‐based magnetostrictive magnetometer

The principles of operation of a microelectromechanical (MEMS)‐based magnetometer designed on the magnetoelastic effect are described. The active transduction element is a commercial (001) silicon microcantilever coated with an amorphous thin film of the giant magnetostrictive alloy Terfenol‐D [(Dy0.7Te0.3)Fe2]. In addition to the magnetostrictive transducer, basic components of the magnetometer include: (a) mechanical resonance of the coated‐microcantilever through coupling to an ac magnetic field; and (b) detection by optical beam deflection of the microcantilever motion utilizing a laser diode source and a position‐sensitive detector. Currently, the sensitivity of this MEMS‐based magnetostrictive magnetometer is ∼1μT.