A 100-MHz 32-array transducer using lithographically-made electrodes and vapor-deposited polyurea film

100-MHz 32-array ultrasonic transducers using polyurea thin film are fabricated and tested experimentally in this paper. The polyurea film is prepared through vapor deposition polymerization, and miniature array electrodes are made with the use of lithographic techniques. Array transducers are prototyped in two different types of configurations. A resonant frequency of about 100 MHz was observed in the electrical admittance. Beam steering experiments and pulse/echo tests were carried out using the prototyped transducers.