Shape-engineered BaTiO3 receivers for ultrasonic powering of modular localized peritumoral therapies

Abstract

Wireless ultrasonic power transfer for implantable medical devices has garnered significant interest, particularly for deeply implanted systems that require reliable energy delivery. This led to the discovery of a nascent discipline, Acousto-Bioelectronics, which studies the transduction of acoustic energy within the human body. In this work, we elucidated the untapped potential of the coupling effect of piezoelectricity and flexoelectricity via a miniaturized pentagonal pyramid-shaped barium titanate ultrasonic receiver for implantable medical devices. Providing reliable power, a highly integrated Acousto-Bioelectronics system augments the controlled generation of light, oxygen, and electric fields for potent multimodal cancer therapy. Combining twelve pyramid receivers forms a dodecahedron, establishing a wireless omnidirectional powering microsystem platform. Optimization through finite element analysis and experimental validation demonstrates that a single unit cell (volume of 18.11 mm³) generates an output power of 2.39 mW (optimized impedance of 400 Ω). This power is sufficient to simultaneously generate light (I = 10.1 mW/cm²), oxygen (4.301 µmol/L/min), and an electric field (up to 3 V/cm), highlighting its potential for localized regional targeted therapy of solid tumors. © 2025 Elsevier Ltd