Abstract:
Over the years, the market demand for flexible and wearable electronic devices is mind blowing that poses new challenges to global energy crisis. Low-power electronic gadgets such as wearable sensors, wireless devices, actuators, and health monitoring devices require microwatts to milliwatts of power for their operation. The conventional method of using batteries as a power supply is an obstacle to the miniaturisation of gadgets, since their periodic replacement and recycling are operational hazards. Scavenging different forms of available energy from our day-to-day activities is considered as the best alternative to overcome the future energy crisis. The search for new energy harvesting techniques from clean and sustainable sources has brought rapid progress in the development of nanogenerators. Among various energy harvesters, triboelectric nanogenerators (TENGs) are designed to convert low-frequency, high-entropy mechanical vibrations into electrical energy. These devices, which act as potential candidates for self-powered operation, have received immense global attention by virtue of their simple operation, higher efficiency, enhanced stability, and cost-effectiveness. Thus, TENG based power solution is proven to be useful for applications like the Internet of Things (IoT) and energy autonomous sensor networks. Incorporation of new materials through innovative designs is actively pursued in TENGs, with the central aim of enhancing their output performance. Layered two dimensional (2D) materials are an ideal choice for this purpose, thanks to their higher lateral size and atomic level thickness. This is because the high specific surface area and capacity for charge trapping of such materials help to supplement the triboelectric charge density and thereby improve the power output. Additionally, the newly reported 2D TENGs have high transparency and flexibility, for usage in foldable and wearable electronic devices. In short, 2D materials present new opportunities in energy autonomous wearable electronics.
