High performance triboelectric nanogenerator based on purified chitin nanopaper for the applications of self-powered humidity sensing, gait monitoring, and hyperhidrosis sensor

Pollution caused by electronic wastes (E-wastes) is a global problem due to the use of haordous materials and chemicals in electronic devices therefore, green materials should be used to reduce the burden on our ecological system. Triboelectric nanogenerators (TENGs) are among those electronic devices that have a huge scope of replacing currently used hazardous materials with green materials as their triboelectric layers and substrates. Herein, we used king mushroom powder as an electropositive layer of a TENG, but its output performance was compromised due to the presence of unwanted elements in it. Chitin was the most desirable element in mushroom powder for achieving triboelectricity therefore, we isolated it via non-acidic approach to fabricate a transparent thin film (234.5 μm) of chitin nanopaper (CN). A significant increase of 287% in the output performance was shown by isolated CN based TENG including higher voltage (151 V) and current (11.4 μA) with a maximum power density of 1.78 Wm−2. The fabricated CN-TENG was used to power micro electronic devices including (50 red LEDs) and charging/discharging 6 different capacitors ranging from 9.5 nF to 47 μF. Furthermore, the potential use of CN as a self-powered humidity sensor was explored by observing its response towards variations in relative humidity (RH). Analysis of obtained results verified the implication of isolated CN as the self-powered humidity sensor with a fast reaction/recovery time (7/10 s) and wide operating range (21–95 %RH). The fabricated device was successfully used for the practical applications of hyperhidrosis sensing and gait monitoring. Electronic devices like CN-TENG proved to be a substantial step-forward in contributing towards reduction of cost and global pollution caused by E-wastes.