Cocklebur-structured design of plant fibers for high-performance triboelectric nanogenerators and pressure sensors

Developing new routes to improve the output performance of triboelectric nanogenerators (TENGs) is an ongoing pursuit for practical applications. Herein, we report a sequential protocol for fabricating a high-performance triboelectric nanogenerator based on cellulose fibers (CF-TENG). High-speed shearing makes the plant fiber fibrillate, resembling a cocklebur seed, which is beneficial for cellulose to expose more hydroxyl groups and silver nanoparticles to grow on the surface of cellulose fibers. The cocklebur-structured fiber design also endows AgNP-modified cellulose fiber sheets (Ag@CF-sheets) with a larger surface area. Moreover, the elevated fiber-fiber compactness of the Ag@CF-sheets is advantageous for the enhancement of the effective frictional area and reduction of the thickness. Hence, the triboelectric performance of Ag@CF-sheets was improved greatly. The proposed design gives the resultant fiber-based TENG outstanding output performance of an open voltage of 142.6 V and current of 31.2 μA. Furthermore, the CF-TENG displays fast response and high flexibility when used as a pressure sensor, serving as a highly sensitive sensor to human motion. This work not only develops an efficient method to fabricate a high-performance CF-TENG but also exhibits great potential of the CF-TENG in human motion monitoring applications.