A high frequency resonant scanner using thermal actuation

Large deflection MEMS scanning mirrors are sometimes difficult to design as they require large clearances to avoid collisions. This paper describes a surface micromachined thermally actuated 1D optical scanner capable of large deflection. An array of in-plane Joule heated buckle beams is configured to produce a torque that rotates a cantilevered mirror away from the substrate. The high-Q structure enables deflection of the mirror through large scan angles when operated at resonance. The RMS heating of the buckle beams at high frequencies coupled with residual stress in the mirror´s cantilever lift the mirror away from the substrate to help avoid collisions during operation.