A Programmable Liquid Ultrasound Transduer

This impedance mismatch largely undermines the energy conversion efficiency and the spatial-access freedom for in vivo ultrasound energy harvester implantation. Here, to the best of our knowledge, we for the first time report a liquid ultrasound energy harvester with an ultralow acoustic impedance of ~1.66 MRayl, which shows near-zero impedance mismatch with biological tissues.

Based on a coupling of magneto-viscoelasticity and magnetic induction, the liquid ultrasound energy harvester can deliver an unprecedentedly high-power density of ~21.63 mW cm-2 at a lower incident spatial peak temporal peak ultrasound intensity of ~1.36 W cm-2. Furthermore, it is programmable, deformable and can be adaptive to the dynamically evolving biological tissue surfaces via arbitrary dimensional architecture design.