Development of miniature hydrophone with PZT film deposited by hydrothermal method

A needle type miniature hydrophone was developed by hydrothermally depositing PZT poly-crystal film with thickness of about 10 /spl mu/m on an end of a titanium wire with diameter of 0.3 mm in this study. It is desirable that hydrophone should have as small shape as possible in order to avoid disturbance in the acoustic field itself. Since the body of the hydrophone developed in this study is a titanium wire with diameter of 0.3 mm, disturbance in acoustic field measurement by our hydrophone can be remarkably reduced. It was confirmed that the receiving sensitivity of our hydrophone was about -280 dB (0 dB=1 V//spl mu/Pa) in the frequency range 1 MHz to 10 MHz.