Mechanically Robust and Transparent Organohydrogel‐Based E‐Skin Nanoengineered from Natural Skin

Abstract

Electronic skins (e‐skins), which are mechanically compliant with human skin, are regarded as ideal electronic devices for noninvasive human–machine interaction and wearable devices. In order to fully mimic human skin, e‐skins should possess reliable mechanical properties and be able to resist external environmental factors like heat, cold, desiccation, and bacteria, while perceiving multiple external stimuli, such as temperature, humidity, and strain. Here, a transparent, mechanically robust, environmentally stable, versatile natural skin‐derived organohydrogel (NSD‐Gel) is nanoengineered through the integration of betaine, silver nanoparticles, and sodium chloride in a glycerol/water binary solvent. The transparent NSD‐Gel e‐skin exhibits outstanding tensile strength (7.33 MPa), puncture resistance, moisture retention, self‐regeneration, and antibacterial properties. Additionally, the NSD‐Gel e‐skin possesses enhanced cold/heat resistance and stimuli‐responsive characteristics that effectively sense environmental temperature and humidity changes, as well as physiological human body motion signals. In vitro and in vivo experiments show that the NSD‐Gel e‐skin confers desired biocompatibility and tissue protective properties even in extremely harsh environments (−196 °C to 100 °C). The NSD‐Gel e‐skin has great potential for applications in multidimensional wearable electronic devices, human‐machine interfaces, and artificial intelligence, generating a versatile platform for the development of high‐performance e‐skins with on‐demand properties.

Ultra-robust, high-adhesive, self-healing, and photothermal zwitterionic hydrogels for multi-sensory applications and solar-driven evaporation

“…Finally, to demonstrate the advantages of our PSBMA-LM@PDA hydrogels in next-generation hydrogel devices, we compared our PSBMA-LM@PDA-5 hydrogel with previously reported representative hydrogels in terms of tensile strength, self-adhesion, self-healing, strain sensing, pressure sensing, temperature sensing, photothermal, and solar evaporation performance, substantiating that our PSBMA-LM@PDA-5 hydrogel exhibited overwhelmingly comprehensive features over other counterparts 4,19,23,25,78–87 (Table S4, ESI†).…”

Skin-like hydrogels: design strategy and mechanism, properties, and sensing applications

“…Therefore, the conductivity of the skin-like hydrogel will gradually increase with the increase of humidity. 96,97 Furthermore, skin-like hydrogels can detect specific substances based on changes in electrical signals. And the reasons for the changes in electrical signals are different.…”

“…83 Finally, there are caustic substances, which can damage the hydrogel and reduce its conductivity, thus changing the electrical signal. 77,96,99,100 The skin-like hydrogel works by reacting with NaOH, a caustic substance, to affect changes in electrical signals. 80 The skin-like hydrogel with this function can well detect the change of special substances to avoid the excessive content which may cause the decrease of sensing ability.…”

Hydrogel-integrated optical fiber sensors and their applications: a comprehensive review

“…The sensor demonstrated high linearity (R 2 = 0.99545) with a detection limit of 26 nM. Electrically conductive hydrogels or smart hydrogels, possessing high water content, biocompatibility, and electrical conductivity, have found their applications in diverse research fields, including tissue engineering and biomedicine, 368 energy storage, 369 sensing (capacitance, temperature, strain, humidity), 204,[370][371][372][373] and flexible electronics. 374,375 However, their widespread application in optoelectronic devices is hampered by conductive hydrogel's poor optical guidance.…”