Force based displacement measurement in micromechanical devices

We demonstrate how force detection methods based on atomic force microscopy can be used to measure displacement in micromechanical devices. We show th e operation of a simple microfabricated accelerometer, the proof mass of wh ich incorporates a tip which can be moved towards an opposing surface. Both noncontact operation using long range electrostatic forces and tapping mod e operation are demonstrated. The displacement sensitivity of the present d evice using feedback to control the tip-surface separation is approximately 1 nm. (C) 2001 American Institute of Physics.