Kinematotropic linkage-based cellular metamaterials with bifurcation motion: Construction and analysis

This paper proposes the design and networking method of a metamorphic Ori-block unit and develops a novel family of cellular mechanical metamaterials. First, a novel 6R (Revolute pair) diamond kinematotropic linkage (DKL) with two bifurcation motions is presented and its kinematic model is analyzed using the improved Denavit-Hartenberg parameter method. Additionally, the screw theory is used to analyze its mobility and verify it has not instantaneity in every configuration. This linkage exhibits two bifurcation motions with one rotational degree-of-freedom (DOF). Moreover, a metamorphic Ori-block unit is designed based on the 6R DKL and optimized to assemble a novel metamaterial cell. According to performance analysis, the first motion mode of this metamaterial cell exhibits a negative Poisson's ratio performance, while the second motion mode involves a large deployed/folded ratio. Based on this metamaterial cell, two methods are proposed for networking cellular metamaterials. On the basis of preserving the kinematic characteristics and performance of the metamaterial cell, an optimized design is conducted, and subsequently the optimized metamaterial cells are assembled into novel cellular metamaterials. This study provides a novel concept for the design and movable network of deployable and programmable cellular metamaterials.