3D printing (also known as additive manufacturing) is a way of constructing three-dimensional objects from CAD (computer-aided design) files or other types of computer models. Many 3D-printers build up objects by depositing successive layers of polymer, though 3D-printing with metals (a form of advanced manufacturing) is an emerging field with the potential to transform how many products are made and repaired. WPI experts on 3D-printing can discuss how 3D printing is used in the production of robots and medical devices, and how 3D printing with metal can be used to repair parts or build new ones, even on the battlefield, among other topics.