Design and characterization of a flexible ribbon-type air-borne electret ultrasound transducer with an anisotropic beam pattern

In this paper, a design of flexible capacitive ultrasound transducer is presented. The transducer consists of electret membrane, patterned spacer, and flexible back plate with tiny holes. We use finite element method (FEM) to give a dynamic analysis and to determine the device performance of our design. The transmitter and receiver characteristics are verified experimentally by measuring the sound pressure level (SPL) and sensitivity. Finally, we discussed the directivity both using FEM and measurement results. The anisotropic beam patterns show effectiveness for sound directivity and can be used to design a better directivity by modifying the configuration of ribbon area.