Ultrasonic power transfer from a spherical acoustic wave source to a free-free piezoelectric receiver: Modeling and experiment

Abstract

Surface acoustic wave ultraviolet photodetectors using epitaxial ZnO multilayers grown on r -plane sapphireContactless powering of small electronic components has lately received growing attention for wireless applications in which battery replacement or tethered charging is undesired or simply impossible, and ambient energy harvesting is not a viable solution. As an alternative to wellstudied methods of contactless energy transfer, such as the inductive coupling method, the use of ultrasonic waves transmitted and received by piezoelectric devices enables larger power transmission distances, which is critical especially for deep-implanted electronic devices. Moreover, energy transfer by means of acoustic waves is well suited in situations where no electromagnetic fields are allowed. The limited literature of ultrasonic acoustic energy transfer is mainly centered on proofof-concept experiments demonstrating the feasibility of this method, lacking experimentally validated modeling efforts for the resulting multiphysics problem that couples the source and receiver dynamics with domain acoustics. In this work, we present fully coupled analytical, numerical, and experimental multiphysics investigations for ultrasonic acoustic energy transfer from a spherical wave source to a piezoelectric receiver bar that operates in the 33-mode of piezoelectricity. The fluid-loaded piezoelectric receiver under free-free mechanical boundary conditions is shunted to an electrical load for quantifying the electrical power output for a given acoustic source strength of the transmitter. The analytical acoustic-piezoelectric structure interaction modeling framework is validated experimentally, and the effects of system parameters are reported along with optimal electrical loading and frequency conditions of the receiver. V C 2015 AIP Publishing LLC.

Analysis of Implantable Ultrasonic Coupling Wireless Power Transmission System

“…Finally, power is supplied to the human implantable device through the receiving power processing module. The transmitting power module generally uses a power amplifying circuit [9][10][11][21][22][23] or an inverter circuit [7,8,13,[18][19][20] to supply power to the transmitting transducer, and the receiving power processing module mainly includes a rectifier circuit and a voltage-stabilizing circuit. Figure 1.…”

“…The ultrasonic coupling wireless power transmission can be applied to the metal environment or the demanding electromagnetic environment [8][9][10]. Therefore, the ultrasonic coupling wireless power transmission can make up for the shortage of the electromagnetic coupling wireless power transmission mode in the direction of power supply for implantable medical devices, and has broad application prospects [11][12][13][14].…”

Focused ultrasound actuation of shape memory polymers; acoustic-thermoelastic modeling and testing

“…37,38 The higher penetrating ability of acoustic waves as compared to light has been used for selective tissue necrosis in controlled volumes. Studies have been conducted reporting the use of ultrasound in acoustic energy transfer systems [39][40][41][42] and for drug delivery [43][44][45] especially from polyelectrolyte micro-containers, 46 multilayered capsules 44,47 and polymer micelles. [48][49][50][51] In their study, Kost et al 43 irradiated ultrasound on a polymer matrix for releasing drugs entrapped in the matrix.…”

Exploiting spatial degrees of freedom for high data rate ultrasound communication with implantable devices

“…Major unavoidable challenges arise from miniaturization including degraded bandwidth, lower directivity, and limited processing capability stemming from packaging and power constraints. 4,9 These challenges have prevented ultrasonic IMDs from reaching the speeds necessary for more complex functionality.…”

“…3 More recently, there has been increased interest in using ultrasonic waves for intra-body communication and power transfer. 2,4 At low MHz frequencies, reduced scattering due to relative homogeneity in tissue density and compressibility as well as low attenuation of about 1 dB·cm -1 ·MHz -1 in soft tissue allow ultrasonic waves to safely propagate much farther in tissue than EM waves. 1 The orders of magnitude slower propagation velocity of acoustic waves in the body (~1500 m/s) also results in millimeter wavelengths around a MHz, allowing for simpler circuits, beamforming capabilities, and smaller transducers.…”