Developing Electrostatically Driven Ultrasound Transducer with High Sound Intensity and High Energy Conversion Efficiency

Abstract

This paper proposes an airborne ultrasound transducer driven with electrostatic force, which potentially enhances applications of airborne ultrasound. The proposed transducer can be fabricated by laminating flexible materials and can be formed as a sheet-like phased array device. As the first step, we fabricated a prototype of a single transducer. In experiments at 44kHz, we obtained 55% electro-acoustic energy conversion efficiency and 8.7Pa sound pressure at 20cm from the circular sound source of 6.4mm in diameter. These basic properties suggest that the proposed method enables a thin and light weight airborne ultrasound phased array that is usable in nonlinear acoustics applications.