A micromachined poly(vinylidene fluoride-trifluoroethylene) transducer for pulse-echo ultrasound applications

A process for manufacturing epoxy-backed integrated poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] transducers using standard microfabrication techniques is reported. The P(VDF-TrFE) is spin-cast over a silicon membrane, which is backfilled with epoxy to yield a wide-band, half-wavelength (/spl lambda//2)-resonant device suitable for pulse-echo use. The main advantages of the fabrication process are the ability to build several devices at a time on a single wafer and the potential for integrating electronics on the same substrate with the transducer. Twelve 31-MHz 2-mm diameter transducers were fabricated on a 2-in diameter silicon wafer. A pulse length of about 100 ns was achieved with a sample device, which exhibited a dynamic range of 40 dB and an insertion loss of 48 dB. The axial resolution of the transducer in healthy vascular tissue was estimated to be 79 /spl mu/m.