New designs of air-coupled ultrasonic transducers using micro-stereolithography

Abstract

Micro-stereolithography, a form of high resolution rapid prototyping, has been used to design and construct novel designs of ultrasonic transducers for use in air. This approach allows for designs to be available that are difficult to produce by other means. The work will describe experiments that have been conducted with capacitive devices in two configurations: planar devices that are based on capacitive micromachined ultrasonic transducers (CMUTs), and those with a spiral geometry backplate for the generation of modified wavefronts. In addition, the fabrication technique has also been used to make structurally-modified materials (so-called metamaterials) to change the emitted characteristics in air. Examples are given of the type of applications for which these ultrasonic transducers could possibly be used.