According to the auditory principle of fish’s lateral line organ, a novel microelectromechanical systems (MEMS) bionic vector hydrophone used for obtaining vector information of underwater sound field is introduced in this paper. It is desirable that the application of MEMS-based piezoresistive effect and bionics structure may improve the low-frequency sensitivity of the vector hydrophone as well as its miniaturization. The bionic structure consists of two parts: high-precision four-beam microstructure and rigid plastic cylinder which is fixed at the center of the microstructure. The piezoresistor located at the beam is simulated to the hair cell of lateral line and the rigid plastic cylinder is simulated to stereocilia. When the plastic cylinder is stimulated by sound, the piezoresistor transforms the resultant strain into a differential voltage output signal via the Wheatstone bridge circuit. Microfabrication technology has been employed for the fabrication of the microstructure and measurement results are given. The experiment results show that the receiving sensitivity of the hydrophone is 197.7dB (0dB ¼ 1V/mPa). The novel hydrophone not only possesses satisfactory directional pattern as well as miniature structure, but also has good low-frequency characteristics, and satisfies the requirements for low-frequency acoustic measurement.

This letter reports a mesopiezoresistive effect in a double-barrier resonant tunneling (DBRT) structure. In a DBRT system, an external mechanical stress causes a tensile strain, and the strain, in turn, affects the resonant tunneling and thereby the resistance. Theoretical analysis was carried out on an AlAs/GaAs/AlAs DBRT structure under in-plane uniaxial tensile stresses. The results show that the tunneling current and resistance of a DBRT structure change significantly with external stress-induced tensile strains. The results also show that the resistance-strain response can be tuned effectively by the external voltage. The effect has potential applications in miniature electromechanical devices.