  In this paper, we study the stability of symmetric periodic solutions of the
comb-drive finger actuator model. First, on the basis of the relationship
between the potential and the period as a function of the energy, we derive the
properties of the period of the solution of the corresponding autonomous system
(the parameter $\delta$ of input voltage $V_\delta(t)$ is equal to zero) in the
prescribed energy range. Then, using these properties and the stability
criteria of symmetric periodic solutions of the time-periodic Newtonian
equation, we analytically prove the linear stability/instability of the
symmetric $(m,p)$-periodic solutions which emanated from nonconstant periodic
solutions of the corresponding autonomous system when the parameter $\delta$ is
small.
