In the electromechanical system presented here (Fig. 9.12), a metallic plate 1 is fixed mechanically and a metallic plate 2 vibrates under the effect of a spring of elastic constant k, of length z and of natural length z₀. The distance between the plates is _ℓ− z and their surface area is A. The capacitance of the parallel plate capacitor is,

The electrostatic potential difference Δφ between the plates is maintained constant by a power supply, which generates a flow of conduction electrons through the circuit. The chemical potential of the conduction electrons on plate 1 and 2 are μ₁ and μ₂. At equilibrium, we assume that the deviation of the plate Δ_z = z − z₀ issmall enough, i.e. Δz0. Determine this deviation Δ_z to first-order.

Transcribed Image Text:

C= €0 1-2 Z