Also, see Flat and Corrugated Diaphragm Design Handbook, by Mario Di Giovanni. This only applies to membrane-based pressure sensors. There is an Russian/Israeli treatise which also deals with more complicated boundary conditions for membrane mechanics (Andreeva, Elastic Elements of Instruments). Of course, non-membrane pressure sensors also exist, and behave according to different physical and mathematical principles.... Albert K. Henning, PhD Director of MEMS Technology NanoInk, Inc. 215 E. Hacienda Avenue Campbell, CA 95008 408-379-9069 ext 101 ahenning@nanoink.net -----Original Message----- From: Roger Shile Sent: Friday, January 02, 2009 9:51 AM To: General MEMS discussion Subject: Re: [mems-talk] mems based pressure sensor Try F = MA