Chain-based lattice printing for efficient robotically-assembled structures

Abstract

Due to the nature of their implementation, nearly all low-level fabrication processes produce solidly filled structures. However, lattice structures are significantly stronger for the same amount of material, resulting in structures that are much lighter and more materially efficient. Here we propose an approach for fabricating lattice structures that echoes 3D printing techniques. In it, a modular chain of specially designed links is “extruded” onto a substrate to produce various lattices configurations depending on the chosen assembly algorithm, ranging from rigid regular lattices with nodal connectivity of 12, octet-truss, to significantly less dense configurations. Compared to conventional additive manufacturing methods, our approach allows for efficient use of nearly any material or combination of materials to construct lattices with programmed arrangements. We experimentally demonstrate that a 3x3x2 lattice structure (287 total links) is fabricated in 27 minutes via a modified robotic arm and can support approximately 1000 N in compression testing. Extrusion-based 3D printing, in which a filament of material is extruded through a nozzle has been widely adopted. Here, Zhe Xu and Aaron Dollar report an approach for fabricating lattice structures in which a modular chain of specially designed links is “extruded” onto a substrate allowing for construction of multiscale structures that are efficient in weight and varied in composition.