The fabrication of highly durable skin‐mimicking sensors remains challenging because of the unavoidable fatigue and physical damage that sensors are subjected to in practical applications. In this study, ultra‐durable ionic skins (I‐skins) with excellent healability and high sensitivity are fabricated by impregnating ionic liquids (ILs) into a mechanically robust poly(urea‐urethane) (PU) network. The PU network is composed of crystallized poly(ε‐caprolactone) and flexible poly(ethylene glycol) that are dynamically cross‐linked with hindered urea bonds and hydrogen bonds. Such a design endows the resultant ionogels with high mechanical strength, good elasticity, Young's modulus similar to that of natural skin, and excellent healability. The ionogel‐based I‐skins exhibit a high sensitivity to a wide range of strains (0.1–300%) and pressures (0.1–20 kPa). Importantly, the I‐skins show a highly reproducible electrical response over 10 000 uninterrupted strain cycles. The sensing performance of the I‐skins stored in open air for 200 days is almost the same as that of the freshly prepared I‐skin. The fractured I‐skins can be easily healed by heating at 65 °C that restores their original ultra‐durable sensing performance. The long‐term durability of the I‐skins is attributed to the combination of non‐volatility of the ILs, excellent healability, and well‐designed mechanical properties.

It is challenging to develop healable elastomers with combined high mechanical strength and good elasticity. Herein, a simple strategy to develop high-performance elastomers that integrate high mechanical strength, enormous stretchability, good resilience, and healability is reported. Through simply complexing poly(acrylic acid) and poly(ethylene oxide) based on hydrogen-bonding interactions, transparent composite materials that perform as elastomers are generated. The as-prepared elastomers exhibit mechanical strength (true strength at break) and toughness (fracture energy) as high as 61 MPa and 22.9 kJ/m, respectively, and they can be stretched to >35 times their initial length and are able to return to their original dimensions following the removal of stress. Further, the elastomers are capable of healing from physical cuts/damages in a humid environment because of reformation of the reversible hydrogen bonds between the polymer components. The high mechanical strength of the elastomers is ascribed to the high degree of polymer chain entanglements and multiple hydrogen-bonding interactions in the composites. The reversible hydrogen bonds, which act as cross-linkages, facilitate the unfolding and sliding of the polymer chains in the composites, thereby endowing the elastomers with good elasticity and healability. Furthermore, flexible conductors with water-enabled healability were developed by drop-casting Ag nanowires on top of the elastomers.

Polymeric antifogging/frost-resisting coatings are suitable for use on flexible substrates but are vulnerable to accidental scratches and cuts. To solve this problem, we present the fabrication of healable, highly transparent antifogging and frost-resisting polymeric coatings via the layer-by-layer assembly of poly­(ethylenimine) (PEI) and a blend of hyaluronic acid and poly­(acrylic acid) (HA-PAA). Due to their remarkable water-absorbing capability, the highly transparent and flexible (PEI/HA-PAA)*50 coatings show excellent antifogging and frost-resisting capabilities even under aggressive fogging and frosting conditions. Meanwhile, these coatings can conveniently and repeatedly heal scratches and cuts several tens of micrometers deep and wide in the same region upon exposure to water because of the dynamic nature of the PEI/HA-PAA coatings. The healability of the (PEI/HA-PAA)*50 coatings provides a new way to design transparent antifogging/frost-resisting polymeric coatings with high flexibility, enhanced reliability, and extended service life.

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