Noncontact humidity sensor overcomes the limitations of its contact sensing counterparts, including mechanical wear and cross infection, which becomes a promising candidate in healthcare and human-machine interface application. However, current humidity sensors still suffer the ubiquitous issue of uncomfortable wear and skin irritation hindering the long-term use. In this study, we report a skin-conformal and breathable humidity sensor assembled by anchoring MXenes-based composite into electrospun elastomer nanofibers coated with a patterned electrode. This composite is highly sensitive to the water molecules due to its large specific surface area and abundant water-absorbing hydroxyl groups, while the elastomeric nanofibers provide an ultrathin, highly flexible, and permeable substrate to support the functional materials and electrodes. This sensor presents not only excellent air permeability (0.078 g cm⁻² d⁻¹), high sensitivity (S = 704), and fast response/recovery (0.9 s/0.9 s), but also high skin conformability and biocompatibility. Furthermore, this humidity sensor is confirmed to realize the recognition of motional states and emotional modes, which provides a way for the advanced noncontact human-machine interface.

非接触式湿度传感器克服了接触式湿度传感器的局限性，包括机械磨损和交叉感染，成为医疗保健和人机界面应用领域的有前途的候选者。然而，目前的湿度传感器仍然普遍存在佩戴不舒适和皮肤刺激等问题，阻碍了长期使用。在这项研究中，我们报告了一种皮肤保形且透气的湿度传感器，通过将基于 MXenes 的复合材料锚定到涂有图案电极的电纺弹性体纳米纤维中来组装。该复合材料由于其大的比表面积和丰富的吸水羟基而对水分子高度敏感，而弹性体纳米纤维提供超薄、高柔性和渗透性的基材来支撑功能材料和电极。该传感器不仅具有优异的透气性（0.078 g cm ^-2 d ^-1）、高灵敏度（S  = 704）和快速响应/恢复（0.9 s/0.9 s），而且还具有高皮肤舒适性和生物相容性。此外，该湿度传感器被证实能够实现运动状态和情绪模式的识别，为先进的非接触式人机界面提供了一种途径。