• Walker, Alan
• Mulholland, Anthony

Abstract

This article considers a theoretical model of an electrostatic transducer with resonating conduits con-nected to the cavities in the backplate. A 1D (in space) model is proposed so that the inverse problem of<br/>optimizing the design parameters of the device for a desired output is not computationally prohibitive.<br/>The mathematical model is described based on matching the acoustic impedances at each interface of the<br/>device. The resulting ordinary differential equation is solved to give the frequency domain response of<br/>the system and the pressure output at the membrane. Derivation of the electrical impedance, transmission<br/>voltage response and reception force response is also provided. The model is implemented to compare a<br/>standard device (no conduits coming from the cavity) with a device with one conduit coming from the<br/>cavity. The model output is collated with experimental data and then used to analyse the maximum pres-<br/>sure output for various cavity and conduit dimensions. The results show a significant dependence of the<br/>device performance on the cavity and conduit dimensions. The incorporation of fluid-filled conduits onto<br/>the cavities in the backplate significantly increases the pressure output as well as the transmission and<br/>reception sensitivities. The results show that a practical transducer design could be achieved by suitable<br/>choices of device geometry and the physical properties of the materials employed

Topics

• impedance spectroscopy
• ultrasonic