High-performance flexible triboelectric nanogenerator based on micropatterned allicin-grafted cellulose film

Developing high-performance cellulose-based flexible triboelectric nanogenerators (TENGs) remains challenging due to the weak surface polarity of cellulose. In this work, allicin-grafted cellulose nanofiber films (Alc-CNF) containing square micropatterns on the surface are fabricated, and their successful application for bio-based TENGs with enhanced triboelectric output performance is demonstrated. Allicin was chemically grafted onto the CNFs through the utilization of 'thio-ene' click chemistry. Square micropatterns with different gaps (40, 50, 60 μm) between patterns were created on the CNF film using lithography, then casting Alc-CNF suspension and drying in cleanroom conditions. The Alc-CNF TENG, having a 50 μm gap between the patterns, showed an output power of 87 μW (387 mW/m²), 260 times larger than the pure CNF TENG and 35 times larger than the no-patterned Alc-CNF TENG. The performance is related to the higher surface polarity, electron-donating tendency, and surface roughness of the Alc-CNF film.