A Memristive System Based on an Electrostatic Loudspeaker

The memristor (a memory–resistor) is a fundamental two-terminal circuit element with a nonlinear relationship between the integral of the voltage and the charge. In the literature, the research interest in the development of new memristive systems is growing, due to the potential applications as analog memories or as synapses in neuromorphic systems. In this paper, the possibility of using an electrostatic loudspeaker as a memristor-based system is explored. This kind of loudspeakers use a thin flat polarized diaphragm, usually consisting of a plastic sheet coated with a conductive material, between two electrically conductive plates, with a small air gap between them. When an electrostatic field is applied to the plates, a force is exerted on the charged diaphragm, and its resulting movement drives the air on either side of it. To get a memristor, the deformation of the diaphragm is here converted in a resistance value using a strain gauge attached over it. A mathematical model of the system is developed. Simulation results show that the device based on the combination of an electrostatic loudspeaker and a strain gauge has all the properties of the memristive systems.