Recent advances in nanogenerators for wearable electronic devices

The advancement of triboelectric nanogenerators (TENGs) and piezoelectric nanogenerators (PENGs) have impacted different fields of emerging technological applications by changing wasted mechanical energy into useful electrical energy. Specifically, TENGs and PENGs contribute as a power source for different applications, such as health and fitness real-time monitoring and therapeutic interventions and flexible smart fabric wearable devices for a variety of applications, and also contribute to intelligent transportation and security applications, including vehicle safety systems and IoT-based security feedback and alerts. Furthermore, it highlights environmental monitoring applications, including air quality monitoring and air purification. This Review introduces recent advancements in TENGs, PENGs, and hybrid NGs by introducing structural designs, working mechanisms, device materials, output power, and diverse applications. With the growth of device miniaturization and material discipline, NGs offer innovative solutions for sustainability and off-grid electronics. Future research should emphasize increasing energy conversion efficiencies, durability, and washability to facilitate self-powered wearable electronics.