Frequency Tuning of Micro-beams using Electrostatic Pull-in

摘要

The work reported shows how the frequency of vibration of simple beam structures can be changed significantly through the action of electrostatic pull-in. The application of a voltage between a cantilevered beam and a supporting, but insulating, substrate will eventually cause the beam to become attached to the substrate. This changes the supporting conditions, the free length of the beam and thus its natural frequency. Test micro-beams have been fabricated from surface electro-deposited gold and the dynamic characteristics of these beams have been measured, for a range of 'pull in' voltages, using laser Doppler vibrometery.