Engineering squandered plant protein into eco-friendly triboelectric films for highly efficient energy harvesting

For biological triboelectric nanogenerator (bio-TENG), its inherent deficiencies such as low output power density, monotonous triboelectric behavior, and limited choice of triboelectric materials greatly restrict its wide-scale application. For remedy this, a typical plant protein of rice glutelin (RG) recycled from by-product of starch industry was utilized as a model to investigate the mechanism of triboelectric charging behavior related to protein structure. Using a facile interface-engineering technology of pH-cycle as the research method, the secondary structure of RG strongly influenced its triboelectric property is discovered and the possible mechanism was proposed and verified. Based on this, we achieved ~16 times promotion of output and enabled manipulation of the triboelectric performance of the protein. In this way, not only can we recycle wasted resources back to more valuable areas, but the adjustable properties of proteins as soft matter also highlight their potential as biomaterials in sustainable triboelectric electronic applications such as next-generation intelligent packaging, wearable, and implantable medical devices.