Ultrasound-Driven Triboelectric Nanogenerator with Biocompatible 2-Hydroxyethyl Methacrylate

Ultrasound-driven triboelectric nanogenerators (TENGs)were recentlyproposed as an energy solution technology for a sustainable lifespanof implantable medical devices (IMDs). While the improvement of ultrasoundtransmission is crucial for achieving high energy generation, researchon the material properties of ultrasound-driven TENGs is still inits initial stage. In this work, multifunctional, biocompatible 2-hydroxyethylmethacrylate (HEMA) is suggested as both an encapsulation and triboelectriclayer for an implantable, modulus-tunable ultrasound-driven TENG (IMU-TENG).By adjusting the acoustic impedance of HEMA to be suitable for thesurrounding environment, the ultrasonic transmission coefficient isabout 10 times higher than that of a titanium (Ti) plate. Under invivo conditions, the IMU-TENG generates sufficient energy to chargea 100 & mu;F capacitor 3.7 times faster than the case with a Tiplate. This strategy of using multifunctional HEMA for high-performanceultrasound-driven TENGs could be a promising energy solution for low-poweredIMDs.