P3R-5 Novel Capacitive Ultrasonic Transducers Fabricated Using Microstereolithography

Capacitive micromachined ultrasonic transducers (cMUTs) have been developed using microstereolithography fabrication with architectures comprised entirely of partially metalised photopolymer. These devices derive considerable advantages from rapid prototyping technology, in that they are cheap to produce, and benefit from the design-to-product lead times inherent in the production of components using stereolithography. To date membranes have been produced with thicknesses ranging from 30 to 90 mum with aspect ratios in the order of 100-1000. These devices have been shown to operate both as transmitters and as receivers of ultrasound in air and water. In air, they have a bandwidth approaching 100 % with a centre frequency of 100 kHz. Operation in water at frequencies of up to 5 MHz has also been demonstrated