In this paper, we investigated the effect of dehydration on mechanical and physicochemical properties of Au (Gold) - and Pd (Palladium) -IPMC using water as solvent. By comparison, the difference of the water content of two types of IPMCs mainly depends on the morphology of surface electrodes bonded both sides of IPMC. During the dehydration process, we find that the tip deformation increases at the early stage of actuation, and then they gradually decrease with weight loss of water. And the Au-IPMC generates larger deformation than Pd-IPMC in each stage due to lower resistance of electrode layers, the maximum of which reach up to 17.4mm and 13.1 mm for long strips with the same free dimensions (35 mm x 5 mm), respectively. Their mechanical and physicochemical parameters, such as stiffness, surface resistance, capacitance and cyclic voltammograms (CVs), were examined as a function of the time, whose increase or decrease are intensely dependent on water content. The specific deformations of IPMCs are decided by combined effects of various parameters. (C) 2014 Elsevier Ltd. All rights reserved.