A new principle for the design of condenser electret transducers

In this paper we describe a new principle which can be used to design condenser electret transducers. Contrarily to previously described systems, it does not require an air gap between the moving element (electret or electrode) and the back electrode. It utilizes the relative displacement of electrical charges imbedded in the electret during a nonhomogeneous deformation of the system, with respect to the electrodes of the condenser. This inhomogeneous deformation is obtained through the use of superimposed layers of different tensile moduli. We first describe this general principle and present some preliminary sensitivities.