Phase transformation enabled textile triboelectric nanogenerators for wearable energy harvesting and personal thermoregulation

Abstract

The practical applications of environmentally friendly wearable textile triboelectric nanogenerators (t-TENGs) are constrained by inadequate heat dissipation, moisture permeability, and outdoor durability, particularly in humid and high-temperature environments. This study introduces a novel passive cooling strategy by integrating super-hydrophilic titanium dioxide solvent-free TiO2 nanofluids (TiO2 nfs) into cellulose acetate (CA) fibrous membranes (TiO2 nfs@CA) to achieve human comfort and efficient energy harvesting. Interestingly, the phase transformation of TiO2 nfs around boy temperature range (32-38 °C) effectively regulates the surface temperature of TiO2 nfs@CA fibrous membranes. In comparison with pristine CA fabric, TiO2 nfs@CA textile demonstrates exceptional solar reflectance (93.43%), high infrared emissivity (85%), excellent water vapor transport rate (12.6gm-2 h-1), and a significant cooling effect of 4-8 ℃ for both human skin and indoor environments. TiO2 nfs significantly enhances their ultraviolet resistance as well as mechanical properties and dielectric properties while improving triboelectric output performance with output voltage (66V), current (2.7 μA), and power density (82mWm-2). And TiO2 nfs@CA t-TENGs exhibit superior multifunctionality in terms of energy harvesting capabilities along with pressure sensing abilities for real-time movement monitoring including foot movements assessment as well as recovery evaluation for human body health maintenance purposes. Overall, TiO2 nfs@CA t-TENGs with the skin-friendly, dyeable, and recyclable properties provides a novel approach towards comfortable self-powered wearable devices that enable practical foot movement prediction alongside health monitoring.