Fully Transparent Piezoelectric Ultrasonic Transducer with 3D Printed Substrate

This work presents the first demonstration of a fully transparent, piezoelectric ultrasonic transducer with a 3D printed substrate. All layers of the transducers were fabricated using optically transparent materials namely: polyvinylidene difluoride (PVDF) for active piezoelectric material, polydimethylsiloxane (PDMS) for a supporting elastic layer, indium tin oxide (ITO) for the conductive electrode, and polymethil methacylate (PMMA) as the substrate. The prototype transducer is 500μm in radius, 100μm in thickness with the active piezoelectric layer, and 20μm in thickness for the inactive layer. The fabricated devices were used to record acoustic signals generated by a commercial ultrasonic transducer driven by 16V peak-to-peak (Vpp) amplitude 3cm away in air medium. The amplitude of the recorded acoustic pressure by the fabricated devices were 70mVpp. We concluded that fabricated devices demonstrate entirely transparent ultrasonic transducers. These results indicate that the approach has the potential for displays applications such as gesture recognitions, and finger print sensing.