Stretchable electronic skins for touchless human-machine interfaces require accurate humidity sensing that is fully decoupled from mechanical strain interference. However, pristine 2D Ti₃C₂T_x MXene films suffer from restacking-induced sluggish kinetics and strain-induced resistance crosstalk. Herein, we report highly sensitive, rapid-response, and electromechanically isolated MXene-based humidity sensor arrays for proximity-sensing electronic skins. To enhance water molecule transport, MXene nanosheets are modified via alkaline intercalation to expand the interlayer spacing, followed by in situ polymerization of polydopamine (PDA) nanoparticles. The hydrophilic PDA aggregates act as hygroscopic spacers, modulating electron tunneling via moisture-induced swelling to achieve a high relative sensitivity of 0.707 /%RH and rapid response/recovery times (1.2 s / 2.3 s). To eliminate mechanical interference, the active composite is integrated onto a heterogeneous substrate consisting of glass-microfiber-reinforced stiff islands embedded in a compliant elastomer matrix. This architecture isolates the active film from strain-induced variations up to 300% strain. Utilizing liquid metal interconnects and a gas-permeable electrospun encapsulation, the fabricated 4×4 sensor array demonstrates high-fidelity spatial moisture mapping and non-contact gesture recognition even under 50% biaxial strain, offering a robust platform for advanced interactive robotics and personalized healthcare.

Stretchable epidermal electronics allow conformal interactions with the human body for emerging applications in wearable health monitoring and therapy. Stretchable devices are commonly constructed on submillimeter-thick elastomer substrates with limited moisture permeability, thereby leading to unpleasant sensations during long-term attachment. Although the ultrathin elastomer membrane may address this problem, the mechanical robustness is essentially lost for direct manipulations and repetitive uses. Here, we report a stretchable, breathable, and washable epidermal electrode of microfoam reinforced ultrathin conductive nanocomposite (MRUCN). The new architecture involves ultrathin conductive silver nanowire nanocomposite features supported on a porous elastomeric microfoam substrate, which exhibits high moisture permeability for pleasant perceptions during epidermal applications. As-prepared epidermal electrodes show excellent electronic conductivity (8440 S·cm⁻¹), high feature resolution (~ 50 μm), decent stretchability, and excellent durability. In addition, the MRUCN retains stable electrical properties during washing to meet the hygiene requirements for repetitive uses. The successful implementation in an integrated electronic patch demonstrates the practical suitability of MRUCN for a broad range of epidermal electronic devices and systems.