Leading this issue are three articles assembled by Associate Editor Karl Grosh addressing MEMs modeling in dynamics and acoustics. I am indebted to Karl for his efforts to highlight an emerging area within our discipline. Your comments and ideas for future focus are always welcome.

This issue will be the last put together by Ray Ramonas, our production editor at ASME Publications in New York. Ray has been associated with JVA since its inception and has worked effectively with all of the former editors of the Journal, as well as with me. While we'll miss him greatly, we'll look forward to hearing about his future exploits as the dean of California surfers. Best wishes, Ray.

Larry Bergman, Urbana, IL May 27, 2004

With the advent of micro-electro-mechanical systems (MEMS), a host of mechanics and dynamics problems have come to the fore. Modeling the dynamics and acoustics of these devices provides a challenge to our existing techniques as well as the opportunity to develop new approaches. MEMS structures can undergo large rotations and strains elastically modeling of these deformations is important for normal operation. Capacitive sensing and actuation are ubiquitous in MEMS devices as are other nonlinear interactions. As such, nonlinear forces are common in MEMS devices.

In addition to theoretical downsizing, experimental techniques must also be specialized for the microscale. In this edition, we have three papers on MEMS modeling which address these issues—but of course there are many other interactions that are important (e.g., viscous effects and micro fluid-structure coupling). In the future, it is hoped that more articles will appear under these covers addressing the dynamics and acoustics of MEMS devices.

Karl Grosh, University of Michigan Ann Arbor, MI February 12, 2004