Stretchable and Conductive Composite Structural Color Hydrogel Films as Bionic Electronic Skins

Abstract

Electronic skins have received increasing attention in biomedical areas. Current efforts about electronic skins are focused on the development of multifunctional materials to improve their performance. Here, the authors propose a novel natural‐synthetic polymers composite structural color hydrogel film with high stretchability, flexibility, conductivity, and superior self‐reporting ability to construct ideal multiple‐signal bionic electronic skins. The composite hydrogel film is prepared by using the mixture of polyacrylamide (PAM), silk fibroin (SF), poly(3,4‐ethylenedioxythiophene):poly (4‐styrene sulfonate) (PEDOT:PSS, PP), and graphene oxide (GO) to replicate colloidal crystal templates and construct inverse opal scaffolds, followed by subsequent acid treatment. Due to these specific structures and components, the resultant film is imparted with vivid structural color and high conductivity while retaining the composite hydrogel's original stretchability and flexibility. The authors demonstrate that the composite hydrogel film has obvious color variation and electromechanical properties during the stretching and bending process, which could thus be utilized as a multi‐signal response electronic skin to realize real‐time color sensing and electrical response during human motions. These features indicate that the proposed composite structural color hydrogel film can widen the practical value of bionic electronic skins.

Smart Polycationic Hydrogel Dressing for Dynamic Wound Healing

“…[55,56] Hydrogel is considered as ideal materials for the development of wearable electronic devices due to their adjustable mechanical property and the advantage of easy functionalization. [57,58] Based on the conductivity of the SA 3 DMC 25 -Gly 80 P 7 hydrogel, we systematically studied the multimodal signal response characteristics of the SA 3 DMC 25 -Gly 80 P 7 hydrogel.…”

Ultra‐Sensitive, Deformable, and Transparent Triboelectric Tactile Sensor Based on Micro‐Pyramid Patterned Ionic Hydrogel for Interactive Human–Machine Interfaces

“…Wearable and functional electronics, especially those of ultrasensitive, transparent, flexible, and stretchable devices, are urgently demanded by human beings. [ 1 , 2 , 3 , 4 , 5 , 6 , 7 ] Various wearable devices based on mechanical sensors, flexible electronic skins, and artificial intelligence have been designed and introduced into our lives, [ 8 , 9 , 10 , 11 , 12 , 13 ] promoting the rapid evolution of human sciences and technologies. Combined with the integrated circuits and human–machine interface system, the transparent, deformable, and microscale mechanical sensors demonstrate their promising prospects for the future intelligent sensor system, [ 14 , 15 , 16 , 17 ] robot manipulation, [ 18 , 19 , 20 , 21 ] and digital twin applications.…”

A Skin‐Like Pressure‐ and Vibration‐Sensitive Tactile Sensor Based on Polyacrylamide/Silk Fibroin Elastomer

“…As the largest organ of the human body, skin is composed of collagen and elastin fibers. Based on the noncovalent interactions between collagen, fibers, water, and biomacromolecules, the skin possesses a nonlinear stress-strain relationship SA mechanoreceptors based on changes of resistance, capacitance, or structure color, [11,14,[17][18][19][20][21][22][23] there are limited reports about the vibration sensors based on elastomers mimicking FA mechanoreceptors. The only pressure-or strain-sensitive elastomer is not sufficient for achieving the function of tactile perception, which is a complex process including the detection of both static pressure and dynamic vibration.…”

“…[5][6][7] Recently, double network (DN) hydrogel especially based on polyacrylamide (PAM) and natural biopolymer has emerged as smart elastomers which achieved skin-like mechanical performance, such as high strength and toughness. [8][9][10][11] In this context, Hou [12] fabricated a PAM/gelatin DN hydrogel by introducing macromolecular microspheres. This DN hydrogel not only exhibited a high fracture strength of 1.48 MPa and a fracture strain of 2100% but also showed rapid recoverability and fatigue resistance.…”