Figure 3.

Electric circuits switched by water and water/MSO switch pair using DNA/DEX‐g‐DOPA hydrogel as dynamic wires. A) Digital photos of the hydrogel with volumetric responsiveness upon water. When the hydrogel was taken out from water, the volume of hydrogel was only one‐tenth of that in water within 1 s. When soaked in water again, the hydrogel returned to its birth volume. B) Cyclic voltage–current curve of the electric circuit switched by adding/removing water. C) Cyclic voltage–current curve of the electric circuit that used water and MSO as the switch pair. D) Current‐time curve of the electric circuit by replacing the solvents (MSO and water) repeatedly, demonstrating the stability of the electric circuit.