Chitosan-based electroactive hydrogel

A natural amphoteric polyelectrolyte hydrogel film was prepared by solution blending of chitosan and its derivative carboxymethylchitosan, and cross-linked with glutaraldehyde. Under electric stimulus such a hydrogel quickly bends toward one electrode, showing an electrical sensitive behavior. Because of its amphoteric nature, the hydrogel bends either toward anode (pH ≤ 7) or cathode (pH > 7), depending on the pH of the electrolyte solution. Besides pH value, other factors, such as ionic strength, electric field strength, thickness of the hydrogel and the amount of cross-linking agent also influence the electromechanical behavior of the hydrogels. Compared with chitosan/carboxymethylcellulose hydrogel, which we reported previously, chitosan/carboxymethylchitosan hydrogel exhibits better overall mechanical properties and electrical sensitivity, suggesting its great potential for microsensor and actuator applications, especially in the biomedical field.