Co-fabrication of live skeletal muscles as actuators in A millimeter scale mechanical system

Functional muscle tissue holds promise as a practical actuator for use in engineering applications. Previously, functional live-cell muscle actuators used for robotics have not scaled greater than about 10 µm, the size of a single monolayer of cells. We present a method to produce larger scale muscle actuators fully integrated into a mechanical structure. We use manufacturing techniques including printing a mold, pouring a molded part, and deposition of cell suspension. Our method allows for co-fabrication of actuator and mechanism through muscle self-assembly. We incorporate muscle construct technologies such that the muscle is fully 3D, anchored, and aligned, yielding a 10 mm long and 0.5 mm thick aligned muscle actuator. By co-fabricating the mechanism and actuators, the muscles are produced and used in the same environmental conditions, the process is more robust and repeatable, and evaluation of performance is under identical conditions to those in which the actuator is used. By using the presented method, variable geometry and multiple degrees of freedom can all be incorporated in a single mechanical structure.