Necessity, once again, has proven itself to be the mother of invention, with 3D printing playing the role of enabler. Marathon runner Maximilian Peter, who works as an engineer at Wacker Silicones (Munich, Germany), longed for an athletic shoe with shock-absorbing insoles and a perfect fit. Holding a doctorate in chemical engineering and through his daily activities at Wacker, he quickly identified the best material for this application, silicone, and the appropriate manufacturing process, 3D printing. Just one problem: Silicone parts can only be injection molded, a prohibitively expensive process for custom products, and no suitable 3D printing materials were available. The solution? A novel silicone formulation and a new approach to the 3D printing process, which Wacker described in its Interim Report for January to June 2015.
Peter brainstormed with engineers at Ingenieure GmbH, a product development and prototyping bureau in Ergolding, Germany, to find a way to 3D print using silicone. "Until now, it has been impossible to print with elastomers. No suitable processes were available," Peter is quoted as saying in the report. Within about a year, however, the group had developed an additive process that would work with silicone, which can't be melted and shaped into a final product the way that thermoplastics and metals can.