Antagonistic living muscle actuator

We propose a muscle actuator with antagonist muscle to mimic configurations of our body. In the muscle actuator, two bundles of muscle fibers are arranged in plane symmetry, and a flexible substrate with electrodes is located at the center of the two muscle bundles. Owing to the existence of the antagonist muscle, tension of the two muscle bundles balanced with each other during culture. Moreover, selective contractions of each muscle bundle allowed the substrate to bend bidirectionally. From the contraction results, we were able to estimate a contractile force of muscle and a reaction force of antagonist muscle. We believe that the muscle actuator is useful not only as an in vivo-like actuator in biorobotics field, but also for revealing biological properties of muscle with antagonist muscle.