A Method to Measure Beam Deflections in Different Resonance Modes Piezoresistively and its Incorporation into 2D Optical Microscanners

Abstract

This paper describes a sensing technique to detect beam deflections caused by the two different vibration modes, i.e. bending and torsion modes of a micro cantilever, separately with two piezoresistor bridge circuits. Fabrication process to incorporate this detection circuitry into a two-dimensional optical microscanner together with the signal processing circuitry for self-sustaining vibrations are presented, which enables a compact feedback control of the two-dimensional optical scanning. Prototype optical scanners with this detection circuitry and magnetostirictive actuation have been fabricated with MEMS technology and tested to verify this technology.