Multi-layer piezoelectret hydrophone for ultrasonic applications

Thin porous flexible films with large piezoelectric effects are now known as ferroelectrets or piezoelectrets. Recent developed techniques for fusing fluoropolymer films with well-controlled cavities have promoted a new class of this material, thermally more stable. In this work, we investigate the underwater behavior of a multi-layer piezoelectret with open tubular channels. For this propose an electrically shield and waterproof aluminum housing was developed. The piezoelectret was tested and results were compared with those obtained from a commercially available hydrophone.