Conductive double‐network hydrogel for a highly conductive anti‐fatigue flexible sensor

Abstract

Improving the mechanical properties of hydrogels is a prime example of their large-scale, diverse applications. Herein, we report a one-pot method for preparing a double network system hydrogel where the polyvinyl alcohol served as the first polymer backbone, acrylamide as the second network, and N, N 0 -Methylenebisacrylamide as the cross-linker, and the prepared hydrogels presented excellent mechanical properties with 1168% tensile strain and 598 kPa compressive strength. Through the metal-ligand bonds, an electrolyte solution containing Cu 2+ was introduced into the hydrogel, which exhibits higher water retention than other electrolyte-containing hydrogels. Specially, the hydrogel was able to retain water for 8 h under extreme dry conditions at 60 C. The GF value was calculated to be 0.124 when the strain was 0%-64.2%. Furthermore, the hydrogel flexible sensor can detect changes in ambient temperature. When the ambient temperature rises, its relative resistance also tends to rise. In conclusion, this hydrogel sensor offers great potential applications in flexible sensors.

Fabrication of PEG‐anthracene/alginate double‐network hydrogels and their application in photolithography

“…Comprehensive researches showed that a dramatic enhancement in the mechanical strength could be obtained when the ratio of the two networks was within a suitable range 18 . Owing to their extremely high mechanical strength and toughness, double‐network hydrogels have received extensive attention, receiving wide applications in the fields of material chemistry, biomaterials, medical engineering, and energy chemistry 28–33 …”

“…18 Owing to their extremely high mechanical strength and toughness, double-network hydrogels have received extensive attention, receiving wide applications in the fields of material chemistry, biomaterials, medical engineering, and energy chemistry. [28][29][30][31][32][33] Stimuli-responsive hydrogels belong to a new type of intelligent materials that are responsive to various external stimuli. Their physical and chemical properties can be tuned by the applied stimuli, providing the opportunity of fabricating tailorable dynamic functional materials.…”

Stimuli‐responsive properties of double network hydrogels derived from κ‐carrageenan and poly (acrylamide)

“…12,17 The second network of covalent crosslinking ensures that the hydrogel has sufficient strength and toughness, so that the DN hydrogel possesses enhanced fatigue resistance and reusability, which make it suitable for use as a flexible sensing material. [14][15][16][17][18] Carrageenans (CGs) with sulfonic groups are natural polysaccharides derived from red marine algae. They are now available on industrial-scale biopolymers and applied in the food industry.…”

“…The mechanical property of the DN hydrogel has been greatly altered, mainly because the first network of noncovalent physical crosslinking is suitable for the “sacrificial bond” during the process of strain in materials; moreover, it effectively dissipates energy and maintains the soft covalent network 12,17 . The second network of covalent crosslinking ensures that the hydrogel has sufficient strength and toughness, so that the DN hydrogel possesses enhanced fatigue resistance and reusability, which make it suitable for use as a flexible sensing material 14–18 …”

A Self‐Healing Conductive Elastomer Based on a Polymerizable Deep Eutectic Solvent

“…Conductive elastomers are crucial in reducing the gap between intelligent robots and humans, [1][2][3] given the rapid development of intelligent machines enabled by advancements in electronic devices and materials. Furthermore, systems such as flexible sensors, [4][5][6] intelligent robots, [7][8][9] motion-monitoring equipment, [10][11][12] and supercapacitors [13][14][15] have witnessed DOI: 10.1002/smll.202304828 new developments. Conductive elastomers exhibit mechanical properties such as ductility and toughness as well as conductivity.…”