A vertically-supported two-axial torsional micromirror

A vertically-supported, two-axial torsional micromirror has been successfully demonstrated and analyzed with finite element analysis. The 2 μm-thick polysilicon micromirror, vertically supported on a substrate by locking springs and hinges, was torsionally actuated in the two orthogonal angular directions under AC driving voltage of 2.5 V and DC bias voltage of 5 V to reflect and generate laser light patterns of line, ellipse or circle on a distant screen as controlled by the driving frequency. The scanned and reflected laser light was able to make a circular pattern at f=387 Hz, an elliptical pattern at f=350 Hz, and a line pattern at f=427 Hz. As such, this surface-micromachined micromirror could provide opportunities of making complicated optical systems on a chip.