Urchin-like modified microfibrillated cellulose for humidity-resistant wearable triboelectric nanogenerators

High-humidity environments can cause swelling of triboelectric nanogenerator (TENG) sensing substrates, leading to response hysteresis, impedance attenuation, and electrostatic shielding, thereby reducing device sensitivity and long-term stability. To address this, this study designed and fabricated a micro/nano-structured microfibrillated cellulose (MFC)-hydroxyapatite (HAP)‑carbon nanotube (CNT) membrane. The material forms an urchin-like fibrous structure through self-assembly, combined with a loosely connected MFC-HAP fiber network, synergistically endowing it with hydrophobicity and porous properties. This structure significantly enhances the electrical output of TENGs. Tests show that the fabricated cellulose-based TENG maintains 86.6 % of its initial voltage output at 90 % relative humidity and stable performance after 2000 cycles in 99 % ultra-high humidity. Furthermore, its practicality in wearable sensing was demonstrated through motion monitoring and Morse code transmission. This study innovatively proposes a humidity-resistant TENG design strategy based on micro/nano-structure regulation, providing new theoretical and practical guidance for self-powered sensing in humid environments.