A miniature swimmer actuated by a PZT ring ultrasonic underwater propulsion system

Abstract

The study investigates a novel scheme utilizing the ring transducer for an acoustic underwater propulsion system. Acoustic underwater propulsion systems are well-suited for the inspection and repair of underwater robots due to their small size, high power density, and simple structure. Previous research has focused on self-propelled swimmers utilizing disc transducers. However, the radial vibration component of the disc transducer makes it difficult to provide propulsion for the acoustic underwater propulsion system driven by the acoustic driving force. Pure longitudinal vibration requires a thicker thickness to achieve the same vibration area, resulting in higher impedance and reduced driving efficiency. In this paper, Simulation, and measurements of vibration distribution demonstrate that the ring transducer exhibits a vibration distribution closely resembling pure longitudinal vibration. A prototype swimmer using a ring transducer was fabricated for experimental evaluation by measuring admittance characteristics, zero-speed propulsion, and no-load speed in water.