A polyelectrolyte complex (PEC), composed of chitosan (CS) and hyaluronic acid (HA), was prepared, which exhibited electrical sensitive behavior. The swelling behavior of the CS/HA PEC was studied by immersion of the gel in aqueous NaCl solutions at various concentrations and pHs. The stimuli response of the CS/HA PEC was also investigated in electric fields. When swollen, the PEC was placed between a pair of electrodes, and exhibited bending behavior on the application of an electric field. It also showed a stepwise bending behavior in relation to the magnitude of the electric stimulus. (C) 2003 Elsevier B.V. All rights reserved.