Hydrogel-based stretchable ionic skins have attracted extensive attention as on-skin epidermal electronics owing to their inherent biocompatibility and ionic conductivity. However, the problem that water in traditional hydrogels eventually evaporates as exposed to air largely hinders their long-term sensing applications. Herein, we report an atmospheric moisture-digesting, biocompatible, and breathable zwitterionic skin with high environmental tolerance by introducing a super hygroscopic zwitterion-glycerylphosphorylcholine (GPC) into hydrogen-bonded polyacrylic acid network. The incorporation of GPC endows the zwitterionic skin with very high water-retaining ability (∼18.3 wt% water content at RH 20 %) and thus superior ambient stability more than one month and freezing resistance (freezing point ≈ −74 °C). Moreover, the multiple and reversible physical bonds in the matrix bring excellent stretchability and elastic recovery, good adhesion to various substrates, rapid self-healing, as well as moisture regeneration. The water-processable zwitterionic skin can also be used as conductive inks, utilizing its universal adhesion and adjustable rheology, to customize zwitterionic tattoos by painting or stencil printing, resulting in ultraconformal and seamless contact with irregular substrates. The zwitterionic skin with all these comprehensive advantages is demonstrated to function as a durable non-drying and self-adhesive sensing platform for multifunctional human-machine interfacing and artificial multimodal tactile sensors.

中文翻译：

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用于不干燥和自粘多功能电子产品的大气吸湿两性离子皮肤

基于水凝胶的可拉伸离子皮肤由于其固有的生物相容性和离子导电性而作为皮肤表皮电子器件引起了广泛的关注。然而，传统水凝胶中的水暴露在空气中最终会蒸发的问题在很大程度上阻碍了其长期传感应用。在此，我们通过将超吸湿性两性离子-甘油磷酸胆碱（GPC）引入氢键聚丙烯酸网络，报道了一种具有高环境耐受性的大气吸湿、生物相容性和透气性两性离子皮肤。GPC 的加入赋予两性离子表层非常高的保水能力（相对湿度 20% 时含水量约 18.3 wt%），从而具有超过 1 个月的优异环境稳定性和抗冻性（冰点约 -74 °C）。而且，基体中的多重可逆物理键带来优异的拉伸性和弹性回复性、对各种基材的良好附着力、快速自修复以及水分再生能力。可水处理的两性离子皮肤还可用作导电油墨，利用其通用的附着力和可调节的流变性，通过绘画或模板印刷来定制两性离子纹身，从而与不规则基材实现超保形和无缝接触。具有所有这些综合优势的两性离子皮肤被证明可以作为多功能人机界面和人工多模态触觉传感器的耐用、不干燥和自粘传感平台。