Locomotion characteristics of foxtail and foxtail type robot according to acting force

A foxtail moves forward when it is pushed by vertical force on flat surface. We could observe that moving distance of a foxtail depends on amount of deflection of a foxtail. In order to mimic a foxtail type robot effectively, we experimentally investigate moving distance of a foxtail according to pushing force, pushing area, and pushing velocity. Then, theoretical analysis on displacement of a nylon barb which related to acting force and deflection are performed. The theoretical result is compared to that of experimental result. Based on the aforementioned study, we fabricated a foxtail type robot. In order to suggest some design parameters of the fabricated foxtail robot, we investigate the relation between displacement and angle of the barb of the robot. Considering locomotion environment of the blood vessel and weight of robot, we suggest range of interaction force between in-body magnet and external magnet that can give 60% displacement of barb´s length.