Chitosan Nanocomposite-Based Triboelectric Nanogenerators with Enhanced Electrical Performance: An Opportunity for Bioelectronics

Abstract

Triboelectric nanogenerators (TENG) based on natural biomaterials are essential for energy-harvesting applications. In this work, an efficient approach was proposed to enhance the electrical performance of chitosan (CS), which is a naturally occurring biopolymer with the incorporation of polyethylenimine-grafted graphene oxide (PEI-GO) nanoparticles. Triboelectric properties of the different weight combinations of PEI-GO in CS were tested against polytetrafluoroethylene (PTFE). An improvement in the mechanical and electrical properties of the nanocomposites was observed in comparison to pure chitosan. Thus, the composite with 10 wt % PEI-GO was used as the positive layer in the TENG device, and an open-circuit voltage (V oc ) of ∼222 V, short circuit current (I sc ) of ∼6.6 μA, and transfer charge (Q sc ) of ∼149.6 nC were observed. Almost a 5.5 fold increase of the output power (∼1465.2 μW) and its power density (∼407 mW/m 2 ) were seen for the nanocomposite in comparison to that of pure CS. The TENG was able to power calculators and wristwatches and light up 126 blue light-emitting diodes (LEDs). Further, a TENG was fabricated with the same polymer (CS and CS nanocomposite) as tribo-layers, where the pure CS polymer acts as the tribo-negative layer and PEI-GOincorporated CS acts as the tribo-positive layer in the CS polymer-based TENG. The device was found to light up 14 white LEDs with the human hand tapping. This study thus presents opportunities for utilizing biomechanical energy found in everyday life to power bioelectronics with bioderived materials.