Design of 3D-Printed Continuum Robots Using Topology Optimized Compliant Joints

Compliant joints are widely used in the structural design of 3D-printed continuum robots as their monolithic structure can greatly simplify the assembly process. However, some highly flexible compliant joints, such as the leaf-spring joints, still suffer from unstable rotation centers when interfered by external forces, which greatly reduces the motion stability of the constructed continuum robots. To cope with this problem, we propose a topology-optimization-based method in this paper to achieve efficient structural design of the complaint joints in continuum robots. With our method, the rotation stability of compliant joints can be improved without causing stress concentration problems. Experiments were also carried out to evaluate the bending performance of the 3D-printed continuum robots equipped with optimized compliant joints. Results demonstrated that, compared to continuum robots with the conventional leaf-spring joints, the optimized robots showed much less twisting deformation caused by out-of-plane loads, which exhibited the high rotation stability of the optimized joints. In future work, the proposed method can be further developed to achieve optimization of other mechanical properties of the compliant joints in continuum robots.