▎ 摘　　要

NOVELTY - A stretchable piezoelectric film comprises a porous cellulose-based polymer, and a piezoelectric active material loaded in pores of the porous cellulose-based polymer. The piezoelectric active material comprises an organic piezoelectric phase, and the porous cellulose-based polymer is bonded to the organic piezoelectric phase by a hydrogen bond. USE - The stretchable piezoelectric film is useful in preparing ultrasonic transducer for ultrasound imaging, visualization of internal defects and damages of an object to be detected, and nondestructive testing, structural health monitoring and medical diagnosis fields. ADVANTAGE - The stretchable piezoelectric film/the ultrasonic transducer simultaneously have the characteristics of excellent stretchability, piezoelectric performance and lower acoustic impedance, and does not need an elastic substrate. In ultrasound imaging, the ultrasonic transducer can adapt to surface contour of the object to be measured with curved, irregular or complex shapes to improve distance consistency between the ultrasonic transducer and the interface of the object to be measured, thereby reducing the reflection of sound energy and waveform distortion, and finally more accurate and high-quality ultrasound imaging results are obtained. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for an ultrasonic transducer comprising the stretchable piezoelectric film, and stretchable electrodes compounded on two opposite surfaces of the stretchable piezoelectric film, where each stretchable electrode is provided with a pole ear.