Polymer-based films for all-in-one piezo-driven self-charging power systems

The evolution of wearable and implantable electronics has been rapidly advancing alongside the emergence of smart technologies. This raises additional requirements on the energy storage system for powering these devices. Self-chargeability is a highly demanded feature that can prolong the service life without the need for an external power supply. The ubiquitous mechanical energy makes it an ideal source for charging an energy storage system by utilizing the piezoelectric effect. Therefore, the incorporation of an energy harvesting component into an energy storage unit to form a highly integrated all-in-one piezo-driven self-charging power system (SCPS) has been attracting extensive attention. Piezoelectric polymer-based films are the key components in SCPSs either as separators or electrolytes, which determine the self-charging performance of the device. This review aims to provide an overview of recent advances in the application of polymer-based films in SCPSs. The configuration and working mechanism of piezo-driven SCPSs are introduced, and key materials used for polymer-based piezoelectric films are summarized. The discussion on latest developments in polymer-based piezoelectric components focuses on materials design and self-charging performance. The future directions and new perspectives for the development of polymer piezoelectric films for SCPSs are also presented. This work may provide guidelines and useful information for practical implementation of SCPSs in wearable and implantable electronics.