A Kirigami-Inspired Metamorphic Double-Loop Linkage With Multiple Single-Degree-of-Freedom Reconfiguration Branches

Reconfigurable mechanisms attract increasing attention for the characteristic to change structure configurations and motion behaviors in various multifunctional systems. By drawing inspiration from a kirigami fold, this paper presents a metamorphic double-loop linkage with multiple single-degree-of-freedom (DOF) reconfiguration branches, which is generated through combining two reconfigurable 6R plane-symmetric linkages. Mobility analysis of the metamorphic linkage is carried out in terms of the screw-loop theory equation, as well as the induced reconfiguration position identification. Then, this paper presents the specific reconfiguration conditions for the two single-loop components in this linkage, and a physical prototype fabricated by 3D printing verifies the ability of configuration reconstruction. Sixteen types of evolved motion branches are constructed by implementing different reconfiguration constraints, respectively, and corresponding kinematic paths are described by employing the specific angle between axes of joints. Furthermore, these evolved motion branches of this metamorphic linkage provide novel examples of mobile assemblies among several fundamental single-loop linkages.