Properties of transverse ultrasonic transducers of ferroelectric polymers working in thickness shear modes

Shear piezoelectric properties of poly(vinylidene fluoride) (PVDF) and copolymer of vinylidene fluoride and trifluoroethylene [P(VDF/TrFE)] have been studied precisely in a wide temperature range from 10 to 400 K. It was found that these polymers have the shear electromechanical coupling factors k/sub 15/ and k/sub 24/ large enough to be utilized for transverse ultrasonic transducers operating in a wide frequency range and in a wide temperature range below 400 K. Shear mode ultrasonic transducers of P(VDF/TrFE) were fabricated and their performances were studied both experimentally and theoretically. The shear polymer transducers are useful for generation and detection of transverse ultrasonic waves.