Stimuli-responsive microfiber-bundle actuator with hierarchical alignment

This paper describes a stimuli-responsive microfiber-bundle actuator that has hierarchical alignment from molecular scale to macroscopic scale. We succeeded in aligning the orientation of molecular scale polymer chains in the stimuli-responsive hydrogel microfiber, which enhances the shrinkage of axial direction of the microfiber. We also bundled the microfibers and constructed a macro-scale bundled microfiber. The actuation of the bundled microfiber was confirmed by stimulating with temperature. We believe that this approach could enhance the performance of functional polymer materials for applications such as biomimetic actuators and soft robots.