Electrically conducting shape memory polymer composites for electroactive actuator

We have tried to apply electroactive shape memory polymer to smart actuator. Electroactive shape memory can be achieved by applying an electric field to shape memory polymer without any thermal heating as conventional shape memory polymers. For it, electrically conducting shape memory composites were prepared by incorporating carbon nanotube into polymer matrix. A segmented polyurethane block copolymer composed of 4,4'-methylene bis (phenylisocyanate), polycaprolactone, and 1.4-butanediol was synthesized to be used as shape memory polymer, and carbon nanotube was used after surface-modification by an acid. It was found that nanotube-reinforced composites could show high electrical conductivity with increased modulus at only several weight percentages of nanotube, and electroactive shape recovery effect more than 80% could be obtained. Consequently, electric field-stimulated shape memory could be demonstrated through combined composites of polyurethane and nanotube.