Multifunctional wearable triboelectric nanogenerators prepared by combined crystallization and diffusion method: High-output, breathable, antimicrobial, and Janus-wettability for smart control and self-powered biosensing

Wearable triboelectric nanogenerators (W-TENG) exhibit significant potential for applications in smart control systems and self-powered biosensing. Thus, developing a feasible, economical, and efficient method to prepare W-TENG with high output and practicality is essential. This paper proposes a strategy for preparing PVDF-based W-TENG using a combined crystallization and diffusion (CCD) method. Compared to electrostatic spinning, the CCD method can prepare multifunctional, high-output W-TENG in much less time. Its simple operation and minimal external factors make it highly cost-effective. Utilizing the CCD method, we developed a breathable, hydrophobic, skin-friendly, antimicrobial, and high-output W-TENG by combining Mxene/PVDF and silver nanoparticle-loaded MXene nanosheets/PVDF/cellulose acetate as the top and bottom layers, respectively. The mechanism of crystal growth and the change in crystal size were analyzed by finite element simulation. The W-TENG features a porous structure ranging from micrometers to nanometers, exhibits high negative electrical properties, and contains numerous capillary channels that facilitate moisture and heat transfer. The hydrophobic top surface and hydrophilic antimicrobial bottom surface allow the W-TENG to effectively absorb perspiration and maintain skin health, while also being self-cleaning. The W-TENG demonstrates an open-circuit voltage of approximately 1200 V (at 4 Hz) and a maximum peak power density of 18.55 W/m² at a load of 8 MΩ. Our W-TENG can remotely control trolley movements and enables real-time, self-powered monitoring of joint motion signals. This work introduces a previously unexplored strategy for preparing W-TENGs with significant practical implications.