Spinned P(VDF-TrFE) Copolymer Layer for a Silicon-Piezoelectric Integrated US Transducer

Abstract

Table I The copolymer of vinylidene fluoride (VDF) and trifluoroethylene (TrFE) has been found to be an excellent ultrasonic (US) transducer material because of its impedance matching with biological tissues and its large electromechanical coupling factor. In order to explore the feasibility of an integrated silicon-piezoelectric copolymer transducer array, we prepared some sample devices by depositing a thin P(VDF-TrFE) layer directly on silicon wafers and by poling the resulting 1.5 micron thin copolymer layer by thermal corona discharge. Pyroelectric and piezoelectric properties were evaluated in those copolymer samples and on casted copolymer film, and compared with those of a commercial PVDF film. Preliminary results suggest that it could be possible to design an integrated transducer for US imaging based on spinned copolymer-silicon technology.