Gamma glycine enhances efficiency of organic hybrid piezoelectric-triboelectric nanogenerators

This study presents a comprehensive exploration of enhancing the electrical output of flexible hybrid piezoelectric-triboelectric nanogenerators (P-TENG) through the incorporation of γ-glycine (γ-GC) into fully organic γ-GC/chitosan (CS) composites. A systematic investigation of the effects of γ-GC content (wt%) on the material characteristics and resulting electrical output signal is conducted. The research demonstrates the pivotal role of optimized γ-GC and CS concentrations in achieving superior performance. Through adherence to the percolation threshold principle, a critical γ-GC content is identified, leading to the attainment of the highest output signal. Three theoretical explanations substantiate this observation: firstly, molecular polarization occurring at the interface; secondly, the establishment of a well-connected filler internetwork; and thirdly, mitigation of air breakdown limitations. The interaction of γ-GC and CS fosters a robust hydrogen bond network, aligning interface polarization coherently. Efficient internetwork connections between γ-GC fillers facilitate facile charge generation and transfer. Furthermore, utilizing an appropriate quantity of γ-GC ensures optimal charge entrapment while circumventing issues related to air breakdown. The optimal electrical output is achieved by using 50% γ-GC, resulting in an open-circuit voltage (V_OC) of 79 V and a short-circuit current (I_SC) of 64 µA. The maximum power output (P_max) registers at 705.96 µW under an external load resistance of 1 MΩ. Importantly, practical applications are demonstrated, including capacitor charging (0.22 μF and 0.33 μF), illumination of 100 LEDs, and operation of a scientific calculator-equipped watch.