High‐Performing and Capacitive‐Matched Triboelectric Implants Driven by Ultrasound

Abstract

In implantable bioelectronics, which aim for semi‐permanent use of devices, biosafe energy sources and packaging materials to protect devices are essential elements. However, research so far has been conducted in a direction where they cannot coexist. Here, we report the development of capacitance‐matched triboelectric implants driven by ultrasound under 500 mW/cm2 safe intensity and realize a battery‐free, miniatured, and wireless neurostimulator with full titanium (Ti) packaging. The triboelectric implant with high dielectric composite, which has ultralow output impedance, can efficiently deliver sufficient power to generate the stimulation pulse without an energy‐storing battery, despite ultrasound attenuation due to the Ti, and has the highest energy transmission efficiency among those reported so far. In vivo study using a rat model demonstrated that the proposed device system is an effective solution for relieving urinary symptoms. These achievements provide a significant step toward permanently implantable devices for controlling human organs and treating various diseases.This article is protected by copyright. All rights reserved

Self-Powered Medical Implants Using Triboelectric Technology

“…The high output performances of VI-TENGs may result from the low operating impedance, benefitting from the high-frequency vibrating contact electrification. 28 Besides, optimizing the spacer dimension affects its electrical output performances, which determines the vibration modes of the triboelectric membrane. On the basis of the superior output performances of VI-TENG, they successfully recharged a commercially available lithium-ion battery with the charging rate of 166 μC s −1 (in water, Figure 2h).…”

“…28,48 To begin with neurostimulation, Kim et al presented a capacitance-matched, ultrasound-driven TENG to treat urinary symptoms. 28 By matching the capacitance through CCTO@P(VDF-TrFE), electrical output of the device is boosted, which reduces the inherently high impedance of TENG and minimizes energy loss. Consequently, the device showed electrical outputs of 21.99 V pp and 0.697 μA pp , which can treat an overactive bladder through tibial nerve stimulation (Figure 4g, h).…”

“…They can be constructed with compact dimensions, offering a diverse range of materials selection, while concurrently exhibiting high power density and operational stability Figure c displays the generated power of the TENGs upon the different mechanical sources. ,,− Utilizing high-frequency vibrations, such as ultrasound, in TENGs takes benefits over those employing low-frequency vibrations with the superior power-generating performances. Furthermore, TENGs driven by high-frequency vibrations are considered highly applicable as an energy solution for medical implants with their relatively low optimal impedance values …”

“…Furthermore, TENGs driven by high-frequency vibrations are considered highly applicable as an energy solution for medical implants with their relatively low optimal impedance values. 28 TENGs are not only being explored as a means to recharge medical implants but are also the subject of an investigation on their utilization as an integral component of electronic medicines (Figure 1d). Taking advantage of the diversity in materials selection, TENG-based medical implants exhibit high flexibility and stretchability, thereby endowing conformal tissue interfaces with minimal immune responses.…”

Theoretical modeling of contact-separation mode triboelectric nanogenerators from initial charge distribution

“…As an emerging technology for converting mechanical motions into electricity, triboelectric nanogenerators (TENGs) have demonstrated great potential in energy harvesting and self-powered sensing. 1–5 With significant advantages in terms of cost efficiency, fabrication easiness and material availability, TENGs have been developed for extensive applications such as in environmental energy utilization, 6–9 wearable electronics, 10–13 human–machine interactions, 14–16 and communication. 17–19…”