A hydrophone using liquid to bridge the gap of a piezo-resistive cantilever

This paper reports on a hydrophone based on a structure in which liquid was used to bridge the gap between a piezoresistive cantilever and the surrounding walls. Due to surface tension, the liquid filled the cantilever's gap while it did not leak through the microscale gap. Evaluation experiments showed that the combination of liquid bridge and cantilever enables the hydrophone to have high sensitivity. Being compact, high sensitivity, low cost, simple fabrication process, the hydrophone is promisingly widely applied in under water communication system and medical field.