Stimuli-Responsive Conductive Nanocomposite Hydrogels with High Stretchability, Self-Healing, Adhesiveness, and 3D Printability for Human Motion Sensing

Abstract

Self-healing, adhesive conductive hydrogels are of great significance in wearable electronic devices, flexible printable electronics, and tissue engineering scaffolds. However, designing self-healing hydrogels with multifunctional properties such as high conductivity, excellent mechanical property, and high sensitivity remains a challenge. In this work, the conductive self-healing nanocomposite hydrogels based on nanoclay (laponite), multiwalled carbon nanotubes (CNTs), and N-isopropyl acrylamide are presented. The presented nanocomposite hydrogels displayed good electrical conductivity, rapid self-healing and adhesive properties, flexible and stretchable mechanical properties, and high sensitivity to near-infrared light and temperature. These excellent properties of the hydrogels are demonstrated by the three-dimensional (3D) bulky pressure-dependent device, human activity monitoring device, and 3D printed gridding scaffolds. Good cytocompatibility of the conductive hydrogels was also evaluated with L929 fibroblast cells. These nanocomposite hydrogels have great potential for applications in stimuli-responsive electrical devices, wearable electronics, and so on.

Adhesive Hemostatic Conducting Injectable Composite Hydrogels with Sustained Drug Release and Photothermal Antibacterial Activity to Promote Full‐Thickness Skin Regeneration During Wound Healing

“…Based on the higher conductivity of rGO than graphene oxide, it was chosen as a component to prepare these HA‐DA/rGO hydrogels. It has been reported that the conductive materials could accelerate the wound healing process . Therefore, the conductivity of these hydrogels was tested.…”

“…It has been reported that the conductive materials could accelerate the wound healing process. [48][49][50][51][52] Therefore, the conductivity of these hydrogels was tested. The dried HA-DA/rGO0 hydrogel presented the lowest conductivity of 0.3 × 10 −4 S m −1 .…”

Copolymer/Clay Nanocomposites for Biomedical Applications

“…Significant contributions have been made concerning stimuli‐responsive hydrogels based on nanoclay‐incorporated copolymers. [ 76,132,154,158 ] Yao et al [ 76 ] reported on fabrication of self‐assembled thermoresponsive nanocomposite hydrogels based on poly( N ‐isopropylacrylamide‐ co ‐acrylamide)/laponite. The prepared nanocomposite bilayer hydrogels exhibited a high extent of elongation and temperature‐responsive swelling/deswelling characteristics even after many repeating cycles.…”

“…[ 77 ] The responsive behavior of the copolymer/clay nanocomposite hydrogels is due to many factors such as phase transition temperature (LCST and UCST), inter/intra molecular hydrogen bond interaction, type of crosslinking, density and protonation–deprotonation of side/pendant groups of the polymer chains. [ 98,102,158 ] Smart hydrogels can be used in biomimetic soft robotics for vehicles, drug delivery, manipulators, and actuators. [ 159 ] On the other hand, nanocomposite hydrogels have been used in regenerative medicine as a cell/protein/drug delivery carrier, as soft implants, and scaffolds due to their exceptional physical and biological characteristics.…”

Tough and conductive polymer hydrogel based on double network for photo-curing 3D printing

“…Specifically, with the growing demand of biomaterials and wearable equipment, electrically conductive hydrogels (CHs) with electrical conductivity and flexible mechanical properties have attracted great interest [9]. CHs have many excellent properties, such as strong adhesion, high porosity, good swelling and biocompatibility, which can transform external stimuli into recorded electrical signals [10][11][12]. Therefore, CHs have been widely used in the preparation of human motion sensor.…”