Integrated MEMS metrology device using complementary measuring combs
David Garmire, Hyuck Choo, Richard S. Muller, James Demmel and Sanjay Govindjee
U.S. Patent 8,079,246. December 2011

Method for fabricating vertically-offset interdigitated comb actuator device
Hyuck Choo, David Garmire, Richard S. Muller and James Demmel
U.S. Patent 7,573,022. August 2009

MEMS-based, phase-shifting interferometer
Hyuck Choo, Richard S. Muller, David Garmire, James Demmel and Rishi Kant
U.S. Patent 7,564,559. July 2009