Vibration sensors for machine control

An efficient method of machine supervision is the measurement of characteristic vibration which can be accomplished by semiconductor devices produced by bulk micromachining. The fabrication is compatible with commonly used Si technology so that MOS stages can be monolithically integrated, in order to amplify the signal converted by the piezoresistive effect. This effect is discussed in comparison with other detection principles. As to the fabrication method, we briefly touch surface micromachining. We describe measurements of vibration spectra of calender rolls in the textile industry. We also show how the signal can be transmitted by optical fibres by means of a light source in hybrid integration.