DOI: 10.5061/dryad.8pm4nv0
title: Data from: Transcutaneous ultrasound energy harvesting using capacitive triboelectric technology

description: A major challenge for implantable medical systems is the inclusion or reliable delivery of electrical power. We use ultrasound to deliver mechanical energy through skin and liquids, and demonstrate a thin implantable vibrating triboelectric generator able to effectively harvest it. The ultrasound can induce the micrometer scale displacement of a polymer thin membrane to generate electrical energy through contact electrification. We recharge a Li-ion battery at a rate of 166 μC/s in water. The voltage and current generated in-vivo by ultrasound-energy transfer reached 6 V and 550 µA in a dog. It shows that capacitive triboelectric electret is the first technology able to compete with piezoelectricity to harvest ultrasound in-vivo and power medical implants.
description: Fig. 1D_ultrasound propagation on deviceFinite element method (FEM) simulation of the ultrasound acoustic pressure propagation through water and the VI-TEG.Fig. 1E_total displacement from the device by ultrasoundFEM simulation of the VI-TEG’s vibrations in water at 5 mm under the 20 kHz ultrasound probeFig.2C_Output voltage at 40M impedance_100ms time intervalTriboelectric voltage at 40 MΩ impedance, measured data in 100ms time intervalFig.2C_Output voltage at 40M impedance_400us time intervalTriboelectric voltage at 40 MΩ impedance, measured data in 400us time intervalFig.2D_Output current_400us time interval_500uA VTriboelectric current at 1 Ω impedance, measured data in 400us time interval (measured in water at 5 mm from the ultrasound probe setup at 20 kHz and 3 W/cm²)Fig.2D_Output current_100ms time interval_500uA VTriboelectric current at 1 Ω impedance, measured data in 100ms time interval (measured in water at 5 mm from the ultrasound probe setup at 20 kHz and 3 W/cm²)Figure 2E_output current data files at different impedanceMaximum current and power depending on the electrical impedance at 5 mm from the ultrasound probe set at a power density of 3 W/cm².Fig. 2E summarized data points plot at 3W cm-2 ultrasound powerSummarized data set: maximum current and power depending on the electrical impedance at 5 mm from the ultrasound probe set at a power density of 3 W/cm²Figure 2F_output current data files at different impedanceMaximum current and power depending on the electrical impedance at 5 mm from the ultrasound probe set at a power density of 1 W/cm².Fig. 2F summarized data points plot at 1W cm-2 ultrasound powerSummarized data set: maximum current and power depending on the electrical impedance at 5 mm from the ultrasound probe set at a power density of 1 W/cm²Figure 3A_Charging capacitors with and without transformerComparison test: a charge of a 4.7 mF capacitor using the integrated transformerFig.3B_charging 700uAh Li ion battery_no transformerA charge of a 700 µAh thin-film Li-ion battery in water at 5 mm from the ultrasound probe set at 3 W/cm².Battery characterizationGalvanostatic analysis of 700 uAh Li-ion rechargeable batteryFigure 3C_output voltage and current of the device at different distance from the ultrasound probeMaximum voltage and current depending on the distance from the ultrasound probe (at 3 W/cm²).Fig.3D_Ultrasound probe power dependance on output voltage and currentMaximum voltage and current depending on the power of the ultrasound probe (at 5 mm).Figure 4E_Output voltage and current of the device located at 0.5cm implantedVoltage, at 40 MΩ impedance, and current, at 1 Ω impedance generated by the VI-TEGs implanted at 0.5 cm under the dog's skin.Figure 4F_Output voltage and current of the device located at 1.0cm implantedVoltage, at 40 MΩ impedance, and current, at 1 Ω impedance generated by the VI-TEGs implanted at 1.0 cm under the dog's skin.