L-lysine-assisted integration of MXene into breathable PVA electrospun nanofibers for humidity-responsive electrical readout and composition-dependent photothermal heating

Surface and interfacial regulation is critical for breathable wearable materials that require stable humidity-responsive electrical output together with auxiliary thermal functionality. Herein, we report a lysine-stabilized MXene/polyvinyl alcohol (PVA) electrospun nanofibrous membrane in which Ti₃C₂Tₓ MXene is incorporated into a porous and vapor-permeable fiber network. This design promotes interfacial compatibility between MXene and PVA, improves its dispersion within the polymer matrix, and preserves a breathable porous architecture that favors water-vapor transport and interfacial moisture uptake. The 2 mg/mL MXene-Lys/PVA exhibits a strong humidity-dependent electrical response, delivering a resistance response of 10,665 over 40–90% RH, and stable operation during repeated cycling and two months of storage. The sensing behavior is mainly associated with water-adsorption-mediated modulation of charge transport within the hydrated polymer/MXene interfacial network, while an additional low-frequency interfacial process emerges under high-humidity conditions. Beyond humidity sensing, the composite largely retains the vapor-transport capability of the porous PVA matrix and simultaneously provides effective photothermal conversion under light irradiation. A garment-mounted PET-ITO prototype further enables real-time wireless transmission of activity-associated humidity-responsive signals. These results show that L -lysine-assisted MXene integration in electrospun porous membranes provides a composition-tunable platform for humidity-responsive electrical readout and photothermal heating demonstrations. Download: Download high-res image (187KB) Download: Download full-size image