Abstract
Recently stimuli-responsive polymer gels have been applied to soft actuators. Especially, electroactive polymers are said to be promising material. Its mechanical motion is controlled by the external stimuli such as a change in solvent composition, pH, temperature and electric field etc. On the other hand, living organisms exhibit an autonomous motion driven by the chemical energy. The gel actuator converts the chemical energy of the oscillatory reaction into the mechanical energy inside the gel. Although the gel is completely composed of synthetic polymer, it shows autonomous motion as if it is alive.