This paper presents a solution of the vibration reduction in the hollow shafts by using magentorehological(MR) elastomer. Proposed active damping structure is built by embedding the MR elastomers whose elastic modulus is controllable by an applied magnetic field. MR elastomers consist of synthetic rubber filled with micron-sized magnetizable particles. For reduction of vibration, dynamic damper of hollow shaft is designed by using MR elastomer and equipped in the hollow shaft for the

Recently, many researchers have been studying new class of biologically inspired robots that exhibit much greater robustness in performance on unstructured environments. Among these robots, inchworm robot can move well in many kinds of environments. Especially, the advantage of an inchworm robot imitating the locomotion of real inchworm can move well in unstructured environments where other wheel or walking robots can't move. In this study, the inchworm robots are designed and the dynamic simulations are done to validate its performance. Magneto-rheological (MR) elastomer which is one of the smart materials is used to give stiffness changes the robot. The stiffness characteristics of MR elastomer can be changed as magnetic field is applied on. Friction characteristics, which are due to variable-stiffness elastomeric actuator with MR elastomers, are identified. Through the dynamic simulation of inchworm robot with MR elastomer, the optimal design as well as the friction coefficient of robot is obtained. As following the optimal design, the robot is manufactured.