3D-MOF-Lattice Inspired Programmable Metamaterials Based on Reconfigurable Polyhedral Origami.

Metamaterials have attracted significant attention due to their unconventional mechanical properties. However, a major limitation of conventional metamaterials lies in the fixed and uniform microstructures, limiting their ability to realize diverse functionalities. Inspired by the network chemistry of the 3D architectures of metal-organic frameworks (MOFs) crystal networks, a reconfigurable design strategy based on polyhedral origami patterns is proposed. Leveraging intrinsic bifurcation behavior, a set of modular units with tunable stiffness and adjustable Poisson's ratios is developed. Both experimental and theoretical investigations confirm that these modules exhibit diverse mechanical responses, including quasi-zero, positive stiffness, bistability, and a continuously tunable Poisson's ratio spanning negative to positive values. By assembling modules in desirable modes, a programmable metamaterial network with customizable mechanical performance is presented. This approach provides a versatile platform for designing multifunctional mechanical metamaterials and offers practical value in applications such as advanced shock-absorbing systems, enhancing versatility and adaptability.