Synergistic Piezo- and Triboelectricity in a Novel Triglycine Sulfate/Bacterial Cellulose/Chitosan Flexible Composite Nanogenerator

Abstract

Organic piezoelectric materials offer sustainable alternatives for mechanical energy harvesting (MEH), yet their potential remains underexplored compared to inorganic counterparts. This study pioneers the use of triglycine sulfate (TGS), a rarely studied organic piezoelectric, within a flexible three-phase composite with bacterial cellulose (BC) and chitosan (CS) for piezoelectric (PENG) and triboelectric (TENG) nanogenerators. Unlike widely researched systems, TGS's unique hybrid organic–inorganic nature is leveraged here for the first time in MEH. Optimized at a 50:50 BC:CS ratio with 40 wt.% TGS, achieves a TENG output of 141.2 V and 93.3 µA post-poling—1.8 and 2.4 fold higher than unpoled samples—driven by TGS's dipole alignment. Separately, the configuration utilizing a 5 wt.% TGS loading yields 13.7 V and 0.19 µA. Advanced characterization (ATR-FTIR, SR-XTM) and simulations (COMSOL, DFT) reveal TGS's synergy with BC/CS roughness, enhancing charge generation. Delivering 118.65 µW cm⁻², the TENG (from the 40 wt.% TGS poled sample) powers a digital watch, showcasing practical promise. This work not only introduces TGS as a novel MEH candidate but also provides mechanistic insights into its polarization, advancing bio-hybrid nanogenerator design.