Novel electrorheological materials based on crosslinked chitosan doped with Y-2(CO3)(3) were synthesized with biocompatible chitosan as the substrate of the materials. The electrorheological performance, surface energy, and thermal decomposition behavior of the materials were investigated as functions of the composition change. The results show that doping Y-2(CO3)(3) can improve effectively the electrorheological performance of crosslinked chitosan with the formation of a metal-polymer complex when the doping degree is suitable. The surface energy plays an important role in influencing the electrorheological properties of the material. (c) 2007 Wiley Periodicals, Inc.