Constant-Force kirigami for scalable, shiftable, stair-stepping and static load-bearing quasi-zero-stiffness metamaterials

Quasi-zero-stiffness (QZS) metamaterials, especially those with multiple plateau characteristic, play an important role in vibration attenuation and isolation systems. However, existing design strategies of QZS metamaterials are limited in the programmability of multi-plateau, that its each stair cannot be tailored either arbitrarily or independently. In this study, a new class of QZS metamaterials is proposed by architecting kirigami cells who embodies kinematic limb-singularity principle in mechanisms. Constant-force behavior, with capability of scalable restoring force and shiftable equilibrium position, is revealed in the cells that unified into one specific kirigami cut topology only. Thus, when stacking a family of monolithic cells into QZS metamaterial, stair-stepping performance is unveiled with each plateau being programmed independently by shifting and scaling each corresponding cell. Theoretical model, combined with simulation analysis and experiments verify the multi-plateau QZS characteristics and vibration isolation with static load-bearing capability. This design strategy, from kinematic perspective, offers new programming tool for QZS metamaterials towards customized mechanical response, instability-free kinematics, and structure compactness.