Current Progress on Power Management Systems for Triboelectric Nanogenerators

This article presents a review on the development of power management systems (PMSs) for triboelectric nanogenerators (TENGs). The TENG is the most recent technology to harvest ambient mechanical energy from the environment and human activities. Its invention was motivated by the prospect of building self-powered systems. The TENG has several appealing advantages, such as high power density, high voltage output, high efficiency at low frequency, and low cost. However, due to the TENG's unique nonlinear electrical property and capacitive behavior, the development of its PMS has presented great challenges as compared to other energy harvesters. The objective of PMS design has evolved from boosting the peak output power, to increasing the energy stored in a capacitor, and to increasing the steady-state output power of a resistive load by using a power converter. Driven by the need to build self-powered systems, the switches in the TENG PMS have evolved from active switches to passive switches. The past decade has witnessed exciting breakthroughs in the development of TENG PMS, yet there are still unlimited opportunities in exploring TENG's energy generation mechanism and vast potential in boosting energy extraction from the TENG by designing effective power converter topologies.