A smart ionic skin patch with on‐demand detachable adhesion has been developed as human–machine interface for physiological signal monitoring. In spite of the multifunctions demonstrated by existing ionic skin, it is still difficult to distinguish different signals simultaneously. Moreover, the secondary damages to the tissues are often overlooked when the adhesive materials are removing from the wound. Herein, a multifunctional biomimetic hydrogel with temperature, mechanical, electrical, and pH response is developed. This hydrogel is designed by in situ polymerizing of hydrophilic anion monomers in a natural cationic polysaccharide to construct multifunctional biomimetic ionic channel. Due to the reversible physical cross‐linked network and thermosensitivity, the mechanical properties, adhesion, and visual effect of the hydrogel can be tuned by changing hydrogen bonding density via phase transition, thus making it an excellent biosafe material for wearable device. The hydrogel is utilized as skin patch intended for monitoring physiological signals stimulated by physical and chemical changes involving pressure, temperature, pH value, and electrocardiograph. Especially, this ionic skin patch can recognize temperature change signals precisely either in broad or extremely narrow temperature range. This smart skin patch can even recognize the pressure and temperature signals in real time and differentiate the signals simultaneously.

Non‐contact human‐machine interaction is the future trend for wearable technologies. This demand is recently highlighted by the pandemic of coronavirus disease (COVID‐19). Herein, an anti‐fatigue and highly conductive hydrogel thermocell with photo‐thermal conversion ability for non‐contact self‐powering applications is designed. Double hydrogen‐bonding enhanced supramolecular hydrogel is obtained with N‐acryloyl glycinamide (NAGA) and diacrylate capped Pluronic F68 (F68‐DA) via one‐step photo‐initiated polymerization. The supramolecular hydrogel can accommodate saturated electrolytes to fulfill the triple function of ionic crosslinking, heat‐to‐electricity conversion, and light response of thermocell. Eminently, the thermocell stands out by virtue of its high seebeck coefficient (‐2.17 mV K−1) and extraordinary toughness (Fatigue threshold ≈ 3120 J m−2). The self‐powering ability under the control of light heating is explored, and a model of a non‐contact “light‐remoted” sensor with self‐powered and sensing integrated performance remote‐controlled by light is constructed. It is believed that this study will pave the way for the non‐contact energy supply of wearable devices.

Ionic skins that demonstrate great advantages in the mechanical properties and multiple sensory capabilities are regarded as an attractive candidate to mimic functions of human skin. However, human skin is vulnerable to be damaged under long-time sunlight irradiation, and most of the current ionic skins also lack a protection against harmful ultraviolet and infrared lights. Herein, this work develops a multifunctional ionic skin based on ionic conductive and light-managing hydrogels via a facile one-step locally confined polymerization. It is mechanically adaptable, able to modulate light in the broadband solar spectrum, and protect human skin from the harmful ultraviolet and infrared lights. Moreover, without complicated processing, the ionic skin enables human-machine interactions via wireless and optical camouflaged Morse codes. We believe this work will promote the development of smart wearable devices with multiple customizable functions.

Supramolecular-polymeric hydrogels by combining low-molecular-weight gelators (LMWG) with polymers have attracted great attention due to their unique double networks. Polymers are generally introduced into LMWG matrix thus enhancing the mechanical...

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