Abstract
The muscle of creatures is bundle structure consisting of a large number of thin muscle fibers. Our research group succeeded the development of thin McKibben artificial muscles which is 1.8[mm] in diameter. The purpose of this research is realization of the mimetic mechanism of muscle structure of creatures. The McKibben artificial muscles expand radially and contract axially. Therefore when thin McKibben artificial muscles are bundled, their expansion of radial direction cause an interference of each other. However the influence of the interference for the output of axial direction has never been clarified. We evaluate the influence of the interference between the artificial muscles by measuring contractive force and contraction ratio.