Self-Adhesive and Conductive Dual-Network Polyacrylamide Hydrogels Reinforced by Aminated Lignin, Dopamine, and Biomass Carbon Aerogel for Ultrasensitive Pressure Sensor

Abstract

Conductive hydrogels have attracted extensive interest owing to its potential in soft robotics, electronic skin, and human monitoring. However, insufficient mechanical properties, lower adhesivity, and unsatisfactory conductivity seriously hinder potential applications in this emerging field. Herein, a highly elastic conductive hydrogel with a combination of favorable mechanical properties, self-adhesiveness, and excellent electrical performance was achieved by the synergistic effect of aminated lignin (AL), polydopamine (PDA), polyacrylamide (PAM) chains, and biomass carbon aerogel (C-SPF). In detail, AL was applied to induce slow oxidative polymerization of DA for preparing the sticky hydrogel containing PDA. Then, C-SPF carbon aerogel was used as a matrix to construct a dual-network structured composite hydrogel by combining with the hydrogels derived from PDA, AL, and PAM. The as-prepared conductive hydrogel displayed excellent mechanical performance, strong adhesive strength, and repeatable adhesivity. The prepared hydrogel-based pressure sensor possessed fast response (0.6 s loading and 0.8 s unloading stress time), high response (maximum RCR = 1.8 × 104), wide working pressure range (from 0 to 240.0 kPa), and excellent durability (stable 500 compression cycles with 30% deformation). In addition, the prepared sensor also displayed ultrahigh sensitivity (170 kPa–1), which was near 4 orders of magnitude higher than the conventional lignin-modified PAM hydrogels. The multiple interactions between hydrogel components and the mechanical properties of hydrogel were also verified by molecular dynamics investigation. Moreover, the excellent cytocompatibility and antibacterial activity of this composite hydrogel ensured high potential in various applications such as human/machine interaction, artificial intelligence, personal healthcare, and wearable devices.

Self-Adhesive, Anti-Freezing MXene-Based Hydrogel Strain Sensor for Motion Monitoring and Handwriting Recognition with Deep Learning

“…Hydrogels are a kind of multifunctional complex polymer material with an obvious three-dimensional network structure and abundant water content. Through dual-network hydrogels, − nanocomposite hydrogels, , macromolecular microsphere hydrogels, − and other strategies, the hydrogel strain sensor has high strength, high toughness, , high tensile property, and self-adhesion. , Due to water loss brought on by crystallization at low temperatures and air drying, the material characteristics of hydrogels may deteriorate, making them damaged, brittle, and non-conductive. These adverse changes may lead to the failure of hydrogel in strain sensors, , nanogenerators, , and supercapacitors , under harsh conditions.…”

Recent advances in adhesive materials used in the biomedical field: adhesive properties, mechanism, and applications

“…146,188,189 When applied to traumatic anastomoses or surgical incisions, they have excellent adhesion, filling damaged areas to stop bleeding and prevent fluid leakage. 190,191 Hydrogels formed in situ can be designed to accumulate serum fibrin exudates to form fibrin bridges, where fibroblasts can migrate and secrete collagen to heal injured tissue. 192,193 Among them, horseradish peroxidase (HRP)-mediated reactions can rapidly and controllably form gels under mild experimental conditions.…”

Zwitterion Functionalized Graphene Oxide/Polyacrylamide/Polyacrylic Acid Hydrogels with Photothermal Conversion and Antibacterial Properties for Highly Efficient Uranium Extraction from Seawater

“…However, their mechanical properties are slightly weak. Previous studies introduced nanomaterials, such as covalent organic framework (COF), [13] lignin, [14] Mxene, [15] and other 2D materials, into PAM/PAA to achieve excellent adsorption and mechanical performance. Therefore, PAM/PAA was introduced into GO via in situ polymerization to obtain GO hydrogels with 3D porous networks.…”