Optimization of Shell packaging for cilium MEMS bionic vector hydrophone

Abstract

Packaging of vector hydrophone influences its engineering application scope. However, the sensitivity of vector hydrophone is greatly reduced after packaging in previous works. Moreover, the vector hydrophone with dipole directivity has the problem of left-right ambiguity. To solve these problems, the shell packaging of cilium MEMS bionic vector hydrophone is optimized in terms of sound-transparent cap and the capability of underwater localization. A blue nitrile butadiene rubber is used as the material for the sound-transparent cap to solve the problem of poor sensitivity after packaging. And in order to solve the problem of left-right ambiguity of a single vector hydrophone, a piezoelectric ceramic tube is integrated into the shell to obtain sound pressure information. In this paper, the packaging process of optimized shell is introduced in detail. Then, the sensitivity test, directivity test and pressure-resisting test of optimized shell are finished. The testing results show that sensitivity of vector information part is increased average 5.6 dB after packaging. And the sensitivity curve depicts that the sensitivity increases 6 dB per octave in the working bandwidth in the range of 63−1000 Hz. Therefore, the optimized vector hydrophone shows a good performance in engineering application.