Development of robot assisted hybrid additive manufacturing technology for the freeform fabrication of lattice structures

Abstract

The extensive study and development of additive manufacturing technologies have allowed not only increased customization of the final parts but especially of their complexity. From such perspectives, intricate and mechanically efficient lattices which maximize their strength-to-weight ratio could be printed. Nevertheless, the fabrication of regular lattices, like octet cells, has been proven to be particularly limited by the layer-by-layer construction process due to the introduction of additional interfaces and/or the requirement of supports. In this work, a hybrid extrusion–photopolymerization process is coupled with a 6-axis robotic arm to allow for the fabrication of layers-less lattices thanks to the use of a custom graphical user interface and control over the printing head orientation. A highly reactive resin is employed as the ink and loaded with silica particles in order to tailor its rheological properties. A good resemblance between the printed components and the digital model is achieved, while their mechanical properties are superior to the ones of the traditionally additive manufactured octets.