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. (C) 2008 Elsevier Ltd. All Fights reserved.