MIT's New 3D Printer Produces a Fully Working Electric Motor in Just 3 Hours — For 50 Cents

A broken motor can bring an automated factory to a halt. Instead of ordering a replacement part that could take days or weeks to arrive — with costly production delays — it may soon be possible to simply print a new one on-site in a matter of hours. MIT researchers have developed a multi-material 3D-printing platform that can fully print electric machines in a single step, using materials costing just 50 cents. The team used their new system to produce a fully 3D-printed electric linear motor in approximately three hours using five different materials. They only needed to perform one post-processing step for the motor to be fully functional — and the assembled device performed as well or better than similar motors made with more complex fabrication methods. The system processes multiple functional materials — including electrically conductive materials and magnetic materials — by using four extrusion tools to handle varied forms of printable material. The printer squeezes them through a nozzle as it fabricates a device one layer at a time. 'This is a great feat, but it is just the beginning,' said Luis Fernando Velásquez-García, in MIT's Microsystems Technology Laboratories and the senior author of the paper published in Virtual and Physical Prototyping. 'We have an opportunity to fundamentally change the way things are made by making hardware onsite in one step, rather than relying on a global supply chain. With this demonstration, we've shown that this is feasible.' Most multi-material extrusion 3D printing systems can only switch between two materials that come in the same form, such as filament or pellet. The MIT team had to design their own system, retrofitting an existing printer with four extruders that can each handle a different form of feedstock. They carefully designed each extruder to balance the requirements and limitations of each material. The electrically conductive material, for instance, must harden without too much heat or UV light because this can degrade the dielectric material. Meanwhile, the best-performing conductive materials come as inks extruded using a pressure system — vastly different from standard heated-nozzle extruders. Strategically placed sensors and a unique control framework ensure each tool is picked up and put down consistently by the platform's robotic arms, with each nozzle moving precisely so every layer of material lines up properly — because even slight misalignment can derail performance. In the long run, this 3D printing platform could be used to rapidly fabricate customizable electronic components for robots, vehicles, or medical equipment — with far less waste than traditional manufacturing. The age of on-demand, on-site fabrication is getting closer.