Fabrication of Biomaterial-Based Triboelectric Nanogenerators: Study of the Relationship between Output Performance and Strain in Dielectric Materials

A triboelectric nanogenerator (TENG) collects thriftless mechanical energy from the surrounding environment and transforms it into electrical energy. This work demonstrated a feasible method for metallizing the polylactic acid (PLA) surface, which was subsequently used as a biomaterial-based TENG electrode material. We demonstrated that microcellular holes and hydrophilic groups (−C-OH and −COOH) were introduced on an alkali-treated PLA sheet surface, subsequently used to absorb Pd²⁺ by means of covalent bonds, which could serve as catalytic centers for the reduction of Ni²⁺. Of note, the Ni-layer deposition mechanism represents a typical island-like growth pattern. To be precise, a Ni-coated PLA sheet was fabricated successfully and used as a TENG electrode material. The device had excellent performances, with a maximum output voltage of about 5.1 V, obtained from 6% strain (the corresponding stress is 32.4 kPa) on the PDMS layer. Furthermore, it revealed that under a stress of 0.14–32.4 kPa and strain of 1.3–6%, a linear regression relation existed between the output voltage and the dielectric material strain, and it was found that the density of electrostatic charge formed on the TENG material surface is 4.1 × 10⁶ C/m². Additionally, the as-fabricated TENG equipment was attached to various positions of the human body and lab to demonstrate the electrical energy obtained from the mechanical movement. It was also used for real-time demonstrations as a self-powered body-tracking device application which may be beneficial in tracking human position counters during self-powered and emergency exercise movements.