High-performance flexible piezoelectric nanogenerators consisting of porous cellulose nanofibril (CNF)/poly(dimethylsiloxane) (PDMS) aerogel films

A novel, simple, cost-effective, and scalable technique was developed to fabricate high-performance flexible piezoelectric nanogenerators (NGs) using porous cellulose nanofibril (CNFs)/poly(dimethylsiloxane) (PDMS) aerogel film. The porous CNF/PDMS aerogel film was prepared by coating a layer of PDMS on the porous surface of a compressed CNF aerogel film produced via an environmentally friendly freeze-drying process. The porous CNF/PDMS aerogel film was then sandwiched between two thin PDMS films, followed by two aluminum foils, to form the flexible NGs. Under periodic external mechanical deformation by an oscillator, the resulting flexible porous CNF/PDMS aerogel film-based NGs exhibited very stable and high output piezoelectric signals; namely, an open-circuit voltage (Voc) of 60.2 V, a short-circuit current (Isc) of 10.1 μA, and a corresponding power density of 6.3 mW/cm3. The electric power generated by these NGs was able to directly turn on 19 blue light-emitting diodes (LEDs) and charge a capacitor up to 3.7 V. Furthermore, these NGs also demonstrated excellent stability and durability. Considering their excellent piezoelectric performance, ease of large-scale manufacturing, and environmental friendliness, this technology provides a promising solution for developing practical, flexible, and self-powered electronic devices.