Flexoelectric Pyramid Ultrasonic Receivers for Powering Miniature Implants

Barium titanate (BTO) nanoparticles-based miniaturized, three-dimensional pyramid receiver is presented for wireless ultrasonic power transfer. A single pyramid ultrasonic receiver can generate an order of magnitude higher output voltage compared to its cube counterpart when (volumes are the same; 45 mm
³
) excited with the ultrasonic waves. The higher performance of pyramid ultrasonic receivers is attributed to the coupling effect of piezoelectricity and flexoelectricity due to the large strain gradient when subjected to stress. The power generated from a single pyramid ultrasonic receiver could light up a UV LED (395nm), which has significant potential for biomedical implants.