Multidimensional wearable self-powered personal thermal management with scalable solar heating and a triboelectric nanogenerator

Global climate change is increasing the frequency of cold events, which can threaten health and enhance the demand for energy, inhibiting the society to prosper in a sustainable way. Having sun as the heat and body radiation as warmth preservation source, the need to save energy is mitigated through personal thermal management (PTM). Herein, we report a self-powered woven Kevlar fiber (WKF)-based flexible PTM device with a porous Ag@Mo_xFe_1−xSe nanostructure (NS) between a substrate of WKF and Ti₃C₂ MXene film dispersed in polydimethylsiloxane (PDMS). Effective thermotherapeutic ability is demonstrated by the composite (80 °C at 3 V through Joule heating). The porous NS between the WKF and MXene/PDMS layers selectively reflected mid-infrared radiation (97.4%) and absorbed UV–vis–NIR (87.1%). The PTM increased the silicone heater temperature by 10 °C in an indoor setting; in direct sunlight, it raised the heater temperature by 20 °C demonstrating its passive and solar heating-mode. The fabricated device harvests energy from human body movements and simulated raindrops, exhibiting high self-powered heating efficiency and has a maximum power density of 1.5 mW cm⁻² at low frequency (5 Hz). The WKF/Ag@Mo_xFe_1−xSe/MXene/PDMS displayed high tensile strength, excellent breathability and durability. This work demonstrates the advantages of this multifunctional energy-reducing device addressing the world energy crisis, which is effective both indoors and outdoors in cold climates, and in sunny and rainy weather.