Impact Printing.

This article introduces the concept of Impact Printing, a new additive manufacturing (AM) method that aggregates malleable discrete elements (or soft particles) by a robotic shooting process. The bonding between the soft particles stems from the transformation of kinetic energy, gained during the acceleration phase, into plastic deformation upon impact. Hence, no additional binding material is needed between the soft particles; the cohesion and self-interlocking capacities of the material itself acts as the primary binding agent. Shooting, and consequent impacting, forces can be modulated and result in distinct compaction ratios. By linearly shooting material, we decouple the deposition apparatus from the produced parts and provide flexibility to the deposition process to potentially build in any directions or onto uncontrolled surfaces. Impact Printing produces parts with formal characteristics standing between brick laying-assembly of discrete building blocks-and 3D Printing-computer-controlled depositioning or solidifying of material. It brings forward a novel digital fabrication method and an alternative to the conventional continuous AM process. This article validates the Impact Printing approach with a series of prototypical experiments, conducted with a robotic fabrication setup consisting of a six-axis robotic arm mounted with a material shooting apparatus, that forms, orients, and projects the soft particles. We will explain and demonstrate its principles and define the fabrication parameters, such as shooting force, shooting distance, and the resulting aggregations' characteristics.