I describe results from my research on optical MEMS at Berkeley Sensor & Actuator Center. High precision microlenses (200~1000m diameters), fabricated utilizing hydrophobic effects and polymer-printing technology, have 343~7862m focal lengths and show /5~/80 wavefront aberrations at 635nm. Batch-processed polarization-beam splitters, made from low-stress Si3N4, produced extinction ratios of 16dB and 21dB at =635nm for transmitted and reflected light, respectively. Micromachined frequency-addressed microlens array can expand the dynamic range of a Shack-Hartmann (S-H) wavefront sensor beyond...