The latest paper in this area is probably by M. Turowski et al. "High-Fidelity
and Behavioral Simulation of Air Damping in MEMS", Intern. Conf. on Modeling and
Simulation of Microsystems-MSM'99, San Juan, Puerto Rico, USA. It contains
references to other papers.
Also by the same author: "Squeeze Film Behavior in MEMS for Large Amplitude
Motion - 3D Simulations and Nonlinear Circuit/Behavioral Models" IEEE/VIUF Int.
Conf. BMAS'98, Orlando, Oct. 27-28, 1998

Regards,

Andrzej Prochaska