Wideband and efficient polymer transducers using multiple active piezoelectric films

Conventional ultrasound imaging transducers suffer from the trade-off between bandwidth and sensitivity, which impedes the optimization of ultrasound image quality. To alleviate this trade-off, a novel non-resonant multilayer PVDF transducer design is suggested. The design allows the overall sensitivity of the PVDF polymer transducer to be significantly improved while retaining PVDF film´s wide bandwidth properties. This is achieved by making use of the pulse compression technique in a multilayer assembly. A detailed theoretical model that allows the performance of the multilayer transducer to be predicted was developed. Experimental data were collected by using a wideband PVDF needle hydrophone. A good agreement between the experimental data and computer simulations was obtained