A facile mechanical energy harvester based on spring assisted triboelectric nanogenerators

Abstract

The advent of the internet of everything emanates the need of powering myriads of small-scale electronic gadgets and smart sensors using new renewable energy solutions. Triboelectric nanogenerators (TENGs) are emerging candidates to meet such requirements by scavenging mechanical energy from the surroundings. Here, we present a facile, scalable and robust TENG based on polyvinylidene difluoride (PVDF) and polymethyl methacrylate (PMMA) films without any complex fabrication steps. A spring assisted TENG (Sa-TENG) operating in contact separation mode has been designed, fabricated and demonstrated for harvesting mechanical energy associated with human activities such as finger tapping, palm tapping and heel tapping into useable electricity. With a moderate finger tapping force, the Sa-TENG has generated an open-circuit voltage of ∼120 V and a short circuit current density of ∼150 μA m⁻². Also, it is shown that the electrical output of the Sa-TENG can be enhanced with an increase in input mechanical energy and the area of contact. The fabricated Sa-TENG has been used for powering electronics gadgets such as LCD clocks, digital thermometers, LEDs and seven-segment displays.