Sebum‐Membrane‐Inspired Protein‐Based Bioprotonic Hydrogel for Artificial Skin and Human‐Machine Merging Interface

Abstract

As an on-skin electronic device, artificial skin shows great potential in medical monitoring and personal electronics, which also holds promise to develop human-machine merging interfaces. However, merging artificial skins with human bodies is largely restricted by the dissimilarity of material compositions in existing artificial skins and biological tissues. Naturally conductive protein is a potential material candidate for artificial skins, nevertheless, it suffers from the critical issue of dehydration which harms its proton conductivity. Inspired by the sebum membrane of human skin, herein, a proteinbased bioprotonic hydrogel (PBH) with reliable water retention ability is reported for artificial skins. The bovine serum albumin with natural proton conductivity is utilized in the PBH, and the glycerol that originally presents on human skin surface is used as an artificial sebum membrane to retain water. The PBH can act as a bioprotonic skin (B-skin) for collecting electrophysiological signals and self-powered sensing. Based on the B-skin, intelligent robot and cellphone control systems are demonstrated. Compared with present artificial skins, this B-skin is all made out of biological materials that are consistent with material components of human skin tissues including proteins, endogenous glycerol, and water. Such a B-skin may enable the development of next-generation human-machine merging interfaces.

Biodegradable Electroactive Nanofibrous Air Filters for Long-Term Respiratory Healthcare and Self-Powered Monitoring

“…When inspiration ended and ready to exhale, the CNT-FME separated from PLA NFMs, resulting in the formation of an electrical potential difference between the PLA NFM and the CNT-FME, which drove the flow of electrons back in the opposite direction of aggregation and gradually restored the original state. 44 The impact of the SREA strategy on the triboelectric properties of TENG is shown in Figure 3g−i, the output voltage of PLA FMs increased from 4.3 V for SP300 to 21.5 V for SP4000 (nearly 5.0-fold increase), the output current increased from 20.5 nA for SP300 to 63.2 nA for SP4000 (over 3.0-fold increase), and the charge quantity of PLA FMs increased from 17.5 to 26.7 nC (over 1.5-fold increase). We calculated the charge density of PLA FMs based on the charge quantity (Figure 3j) and found that the charge density increased from 4.5 μC/m 2 for SP300 to 6.9 μC/m 2 for SP4000, which was crucial for maintaining the stability of surface potentials and ensuring long-term electrostatic adsorption for the self-powered PLA NFMs.…”

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

“…The researchers have designed a pure physical cross-linking skin-like hydrogel composed of bovine serum albumin, glycerin and water, which functions in good contact with the human body, and can be completely degraded by enzymes without any toxic residues, showing high biocompatibility. 7 However, at present, such research is very few. First of all, the strength of most natural substances (proteins, polysaccharides, DNA, etc. )…”

“…As a natural biological organ, skin is composed of all natural substances, mainly proteins, lipids and water. 7 By imitating skin components and introducing natural substances as network components of hydrogels, skin-like hydrogels with excellent biocompatibility can be effectively developed. Natural components commonly used to introduce skin-like hydrogels include polysaccharides (commonly used sodium alginate, chitosan, hyaluronic acid) and proteins (commonly used bovine serum albumin, silk fibroin, gelatin).…”

“…3,4 However, at present, most of the imitation skin materials are made of metals or carbon materials, when applied to the human body, there are problems such as poor mechanical matching degree and poor biocompatibility. [5][6][7] Therefore, in the practical application process, these skin-like materials will show many negative effects, such as not fit the human body and easy to fall off, causing inflammation and so on. 8,9 The structure and properties of hydrogels with three-dimensional water-based network are much similar to human skin, both of which have the characteristics of low Young's Modulus (o3 MPa) and high water content (470%).…”

Recent Progress of Biomaterials-Based Epidermal Electronics for Healthcare Monitoring and Human–Machine Interaction

“…To be specific, compared with rigid electronic devices, epidermal electronics that mimic various properties of human skin can conformally attach onto human skin with irregular surfaces, which is favorable for reducing contact impedance and improving the fidelity of acquired electrophysiological signals [ 9 , 10 , 11 , 12 , 13 ]. More importantly, epidermal electronics can keep its mechanical and electrical properties stable even under severe stretching or twisting, which further makes it suitable for application fields including healthcare monitoring and HMI [ 14 , 15 , 16 , 17 ].…”