QUASIANALOG ACCELEROMETER USING MICROSWITCH ARRAY

This paper describe the development of a quasianalog accelerometer whi ch uses an array of acceleration switches. The investigations are base d on results or fabricated and evaluated single-microswitch sensors. T he new acceleration sensor concept combines the advantage of high EMI immunity and simple signal pre-conditioning circuitry. Important chara cteristics of the laterally moving cantilevers, such as resonance freq uency and switching time, can he determined by a single mask. First te st devices have been fabricated by the use of a special sacrificial-la yer additive technology. This Microform technology combines UV pattern ing of very thick photoresist layers and moulding of the resulting pat terns by electroplated metals. This technology is used for the fabrica tion of laterally driven microswitches, each having a different accele ration threshold. tinder an applied acceleration, the cantilever beam deflects laterally and closes a contact with an electrode. With an ele ctrode on each side of tile cantilever, two directions of acceleration can be measured. A simulation model has been developed which enables the design of quasianalog sensors for different applications. Differen t layouts are created to investigate the basic characteristics. The si mulation results are verified on a shaker using the fabricated lest st ructures of a single-microswitch sensor.