Polymer MEMS pressure sensor arrays for fish-like underwater sensing applications

Blind cave fish are capable of sensing flows and movements of nearby objects even in dark and murky water conditions with the help of arrays of pressure-gradient sensors present on their bodies called lateral-lines. To emulate this functionality of lateral-lines for autonomous underwater vehicles, an array of polymer MEMS pressure sensors have been developed that can transduce underwater pressure variations generated by moving objects. Individual sensors are fabricated using liquid crystal polymer as a membrane material, which gives high robustness and reliability, and higher sensitivity compared with its silicon counterparts. The individual sensor in the array achieves a sensitivity of 90 mV/(m/s) with a high resolution of 25 mm/s. The underwater object detection capability of the array is demonstrated through proof-of-concept experiments. The array is capable of determining the velocity and distinguishing various distances of an underwater stimulus with high accuracy and repeatability.