Large-range large-aperture MEMS micromirrors for biomedical imaging applications

Micromirrors with large scan ranges, large aperture sizes, fast speeds, low voltages and low cost are needed for optical switching, displays and biomedical imaging, but it is very challenging to simultaneously meet all the requirements. This paper introduces electrothermal bimorph based micromirrors that can overcome the challenge. For example, a large-vertical-displacement (LVD) micromirror scans 0.7 mm vertically at less than 25 Vdc. A lateral-shift-free (LSF) LVD generates a piston motion of 0.6 mm and scans more than 30° about two axes at less than 8 Vdc. An inverted-series-connected (ISC) micromirror scans ±30° about two axes with no rotation axis shifts. All these mirrors have an optical aperture of 1 mm. Their resonant frequencies range from 300 Hz to 2 kHz. Some of these micromirrors have been applied in biomedical imaging applications.