From farkmic at yahoo.com  Wed Mar  5 13:34:06 2008
From: farkmic at yahoo.com (faraz khatami)
Date: Wed Mar  5 13:33:17 2008
Subject: [mems-modsim] torsional and vertical damping factor relations?
Message-ID: <751297.92868.qm@web45306.mail.sp1.yahoo.com>

Hi,
   
  I am investigating dynamic characteristics of a torsional rectangular capacitive micromirror made up of a plate suspended by two beams. Clearly we have two modes of motion (torsional and vertical). I have a problem about the relationship between torsional and vertical damping coefficients. I have derived a relationship but don't know whether it is true or not. Knowing that Cvertical=A/h3, from linearized Reynolds equation, where h is gap, and A is a physical parameter that I don?t mind because I just want to derive relationship between Cvertical and Ctorsional. Anyway integrating over the plate to derive the torsional damping factor: int(A/h3*x*dx) gives a relationship Ctor=L2*Cver. This relationship also seems to be true dimensionally. But the problem is that by deriving these equations in fact I have utilized the superposition principal which is true about linear systems. So I would be so grateful if someone told me if this relationship is true as an approximation or if
 not introduced me some references or told me what to do.
   
  Very thanks.
   

       
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