A laser-micromachined multi-modal resonating power transducer for wireless sensing systems

This paper presents the development of a vibration-induced power generator with total volume of similar to1 cm(3) which uses laser-micromachined springs to convert mechanical energy into useful electrical power by Faraday's law of induction. The goal of this project is to create a minimally sized electric power generator capable of producing enough voltage to drive low-power ICs and/or microsensors for applications where ambient mechanical vibrations are present. Thus far, we have fabricated generators with total volume of 1 cm(3) that are capable of producing up to 4.4 V peak-to-peak, which have a maximum RMS power of similar to830 muW with loading resistance of 1000 Omega. The mechanical vibration required to generate this electrical energy has frequencies ranging from 60 to 110 Hz with similar to200 mum amplitude. The generator was shown to generate sufficient power at different resonating modes. We have demonstrated that this generator can drive an infrared (IR) transmitter to send 140 ms pulse trains every minute, and also a 914.8 MHz FM wireless temperature sensing system. (C) 2002 Published by Elsevier Science B.V.