A Flexible Underwater Pressure Sensor Array Using a Conductive Elastomer Strain Gauge

This paper presents a flexible pressure sensor array which is demonstrated to transduce underwater pressure variations produced by moving objects and surface waves. The sensors exhibit a 0.0014 fractional resistance change per 100 Pa, achieving a high 1.5-Pa pressure resolution. The measurement has a repeatability of 22% of the peak amplitude of the pressure waveform, due to creep. Additionally, sensor operation while bent to a 0.5-m radius of curvature is demonstrated. Each sensor consists of a strain-concentrating polydimethylsiloxane (PDMS) diaphragm and a resistive strain gauge made of a conductive carbon-black-PDMS composite. A 1-D array of four sensors with a 15-mm center-to-center spacing is fabricated, and the dynamic response of the sensors is characterized and modeled.