Constructing high-efficiency stretchable-breathable triboelectric fabric for biomechanical energy harvesting and intelligent sensing

Triboelectric fabrics have attracted significant attention in wearable power supplies and self-powered sensors. Simultaneously endowing triboelectric fabrics with excellent electrical properties, good stretchability and breathability remain a challenging issue. In this work, a highly-efficient stretchable-breathable triboelectric fabric is developed by using a porous composite prepared from polyethyleneimine/silica-coated titanium dioxide (PEI/SiO2@TiO2) modulated carboxymethyl cellulose/waterborne polyurethane as the tribomaterial and polyethyleneimine/carbon nanotubes conductive nanomaterial as the electrode. By systematically manipulating the mass ratio of SiO2@TiO2 NPs, PEI and well-dispersed PEI/SiO2@TiO2, the electrical performance of the optimized triboelectric fabrics can be improved by 111% compared with the unoptimized one, and it can deliver a power density of 1.62 W m−2, higher than most other reported stretchable-breathable triboelectric fabrics. The output improvement can be ascribed to the synergistic effect of the enhanced internal polarization of the well-dispersed PEI/SiO2@TiO2 and the double charge transfer mechanism originating from amino groups. More importantly, the triboelectric fabrics exhibit a good elongation of 245% and a high air permeability of 105.1 mm s−1, which is greatly favorable to the wearable comfort of users. Furthermore, the fabric exhibits good durability and stability in electrical performance during continuous dynamic deformation and long-term use, and it can be widely used for body energy harvesting, remote system control and physiological monitoring. This work provides a practical and feasible idea for constructing high-efficiency stretchable-breathable triboelectric fabric and achieves the all-in-one fabrication of triboelectric fabric with promising electrical performance, comfort performance and mechanical properties.