Integrated Design of Highly Porous Cellulose-Loaded Polymer-Based Triboelectric Films toward Flexible, Humidity-Resistant, and Sustainable Mechanical Energy Harvesters

A wearable and humidity-resistant cellulose-based flexible triboelectric nanogenerator (FTENG) device with high performance is proposed here. In this regard, cellulose extracted from cotton was combined with a poly(vinyl alcohol) solution and spray-coated onto a conductive–flexible substrate to develop a highly porous and flexible triboelectric film (HPF) which was employed in the fabrication of a FTENG. The dependence of electrical performance on the surface area was comprehensively studied by varying the surface area of the HPF. Furthermore, the HPF-based FTENG (HPF-FTENG) is lightweight, flexible, and robust; has a low processing cost; and can withstand a humid environment. Thus, the proposed device can be used not only to scavenge various mechanical disturbances within the surrounding environment but also to harvest mechanical energy underwater and in harsh environmental conditions. Finally, the electricity generated by the HPF-FTENG was employed to power various portable electronics, which supports a paradigm shift in the context of wearable and durable mechanical energy harvesters.