Micromachined electrostatic vertical actuator

US5969848A · kind A · utility

Assignee

• The Regents of the University of California · US

Inventors

• Abraham P. Lee · Irvine, US
• Gary E. Sommargren · Madison, US
• Charles F. McConaghy · Livermore, US
• Peter Krulevitch · Pleasanton, US

Key dates

• Filing date: Jul 3, 1997
• Grant date: Oct 19, 1999
• Expiry date: Jul 3, 2017

Classification

• Technology area (CPC G): Physics
• CPC primary: G02B26/06
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A micromachined vertical actuator utilizing a levitational force, such as in electrostatic comb drives, provides vertical actuation that is relatively linear in actuation for control, and can be readily combined with parallel plate capacitive position sensing for position control. The micromachined electrostatic vertical actuator provides accurate movement in the sub-micron to micron ranges which is desirable in the phase modulation instrument, such as optical phase shifting. For example, compact, inexpensive, and position controllable micromirrors utilizing an electrostatic vertical actuator can replace the large, expensive, and difficult-to-maintain piezoelectric actuators. A thirty pound piezoelectric actuator with corner cube reflectors, as utilized in a phase shifting diffraction interferometer can be replaced with a micromirror and a lens. For any very precise and small amplitudes of motion` micromachined electrostatic actuation may be used because it is the most compact in size, with low power consumption and has more straightforward sensing and control options.