Page 278 - Mechanics of Microelectromechanical Systems
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5. Static response of MEMS 265
Figure 5.2 Electrostatic and spring forces versus displacement
It is known that an equilibrium point, one for which the total force,
defined as:
is zero, has stable properties when the force derivative is negative, namely:
The limit point separating the stable region from the unstable one can be
found by solving the equation system:
where the total force F is determined by means of Eqs. (5.2), (5.3) and (5.4).
By solving the equation system (5.6) in terms of position and corresponding
voltage, the following solution is obtained:
The force corresponding to this point can be found by substituting of Eq.
(5.7) into either Eq. (5.2) or Eq. (5.3), and its expression is:
