According to embodiments of the present invention, vibration sensor array includes at least two microelectromechanical systems (MEMS) vibration sensors formed on a substrate. The vibration element of the first vibration sensor is a different type than the vibration element of the second vibration sensor....http://www.google.fr/patents/US7600429?utm_source=gb-gplus-shareBrevet US7600429 - Vibration spectrum sensor array having differing sensors
Vibration spectrum sensor array having differing sensors
