Volume behavior of interpenetrating polymer network hydrogels composed of polyacrylic acid-co-poly(vinyl sulfonic acid)/polyaniline as an actuator

Polyacrylic acid-co-poly(vinyl sulfonic acid)/polyaniline interpenetrating polymer network (IPN) hydrogels were prepared, and an electrical stimulus was applied to the IPN hydrogels in an electrolyte solution, where the IPN hydrogels underwent a change in volume. The IPN hydrogels showed a reversible change in volume on switching the electrical stimulus between the positive and negative electrodes, showing a contraction and expansion of the IPN hydrogels, respectively. The magnitude of the change in volume of the IPN hydrogels increased with increasing applied voltage. The behavior of the IPN hydrogels was very sensitive to the applied electrical stimulus, and this is important in actuator applications.