Large-displacement vertical microlens scanner with low driving voltage

Abstract

We have designed, fabricated, and demonstrated large vertical displacement vertical microlens scanners with low (<10 V) driving voltage using silicon-on-insulator technology. The unique isolated and pre-engaged vertical comb-drive sets and the coupled-torsion flexure design provide both upward and downward piston motions, as well as low driving voltages. Single-directional devices demonstrate maximum static downward displacement of 8 μm at 10 V/sub dc/. Bidirectional devices demonstrate vertical actuation from -6.5 to +9 μm at max 12 V/sub dc/, and a vertical displacement of up to 55 μm peak-to-peak is achieved at the resonance near 400 Hz. The lens motion shows piston motion with a small tilt angle of less than 0.034/spl deg/ and the compensation of the tilt using an isolated comb bank is demonstrated.