A lateral-shift-free and large-vertical-displacement electrothermal actuator for scanning micromirror/lens

This paper reports the design, fabrication and characterization of a novel lateral-shift-free (LSF) large-vertical-displacement (LVD) electrothermal actuator. Both micromirror and microlens holder based on the actuator design have been fabricated by a combined surface- and bulk-micromachining process. A 0.62mm vertical displacement has been demonstrated at only 5.3Vdc for a fabricated 0.8mm by 0.8mm micromirror, and both the lateral shift (10 mu m) and tilting angle (0.7 degrees) are negligible in the full displacement range. The measured resonant frequency of the vertical motion resonance mode is 453Hz.