Conductive double-crosslinked network hydrogel with superior stretchability and self-healing ability

Conductive self-healing hydrogels are a new type of functional material that combine self-healing with conductive properties. They are widely used in flexible and stretchable devices, which require not only self-healing properties and electrical conductivity but also good stretchability. In this study, we used a one-pot process to crosslink and polymerize trivalent iron (Fe3+) with acrylic acid (AA) and acrylamide (AM) into a dual network hydrogel P(AA–co–AM)/Fe3+, with both chemically and physically crosslinked networks. The obtained hydrogels exhibited excellent tensile properties (∼2000% stretchability) and rapid self-healing ability (complete healing at room temperature within 8 h). Furthermore, the Fe3+ gives the hydrogel good electrical conductivity. In addition, a capacitive pressure sensor using the hydrogel as a conductive active layer was fabricated, which proved its application in the field of wearable devices.