Nature Driven Bio‐Piezoelectric/Triboelectric Nanogenerator as Next‐Generation Green Energy Harvester for Smart and Pollution Free Society

Electronics wastes (e‐wastes) are the major concern in the rapid expansion of smart/wearable/portable electronics in modern high‐tech society. Informal processing and enormous gathering of e‐wastes can lead to adverse human/animal health effects and environmental pollution worldwide. Currently, these issues are a big headache and require the scientific community to develop effective green energy harvesting technologies using biodegradable/biocompatible materials. Piezoelectric/triboelectric nanogenerators (PNGs/TNGs) are considered one of the most promising renewable green energy sources for the conversion of mechanical/biomechanical energies into electricity. However, organic/inorganic material based PNGs/TNGs are very much incompatible, and considered e‐wastes for their non‐biodegradability. This review covers potential uses of biodegradable/biocompatible materials which are wasted every day as nature driven material based bio‐nanogenerators with a particular focus on their applications in flexible PNGs/TNGs fabrication. Structural investigation and possible working principles are described first in order to outline the basic mechanism of bio‐inspired materials behind energy harvesting. Then, energy harvesting abilities and the mechanical sensing of bio‐inspired integrated flexible devices are discussed under various mechanical/biomechanical activities. Finally, their potential applications in various flexible, wearable, and portable electronic fields are demonstrated. These bio‐inspired energy harvesting devices can make huge changes in fields as diverse as portable electronics, in vitro/in vivo biomedical applications, and many more.