Diatom frustule and cellulose nanofibril for bio-triboelectric nanogenerators and self-powered breathing sensor

Abstract

Triboelectric nanogenerators (TENGs) for harvesting mechanical energy are attracting significant research interest due to their simple mechanism and high power density which introduce them as promising device for small size and portable smart electronics. Developing green TENGs by application of biodegradable and biocompatible materials for harvesting energy is required for the current modern society. However, compared with synthetic materials, the biomaterials generate rather lower charge by contact electrification and improving of output power of bio-TENGs still remains a challenge. Cellulose, the most abundant biopolymer, is a strong, light-weight, flexible, and durable sustainable material that can be used for TENG fabrication. In this study, we introduced diatom bio-silica as a biomaterial additive to enhance the output performance of cellulose-based TENG. Having a highly porous three dimensional (3D) structure decorated with features at nanoscale, large surface area, abundancy, and low price make diatom frustule an excellent candidate material for bio-TENGs. Diatom frustule-nanocellulose bio-composite is mechanically strong, electron-rich, and low-cost and frictionally rough which enhanced the output performance of bio-TENGs. In addition, cytotoxicity study and s biocompatibility test on rabbit skin suggested that the diatom frustule-nanocellulose composite was biologically safe. Moreover, a practical application of the DF-CNF TENG was examined with a self-powered smart mask for human breathing monitoring.