3D-Printed Motor Platform Could Speed Up Hardware Production

Most 3D printers are designed to produce plastic parts, such as prototypes, housings for electronics, or decorative objects. Building a working electric machine is far more complicated. Unlike a typical plastic print, devices like motors need different regions to do different jobs: some conduct electricity, others insulate it, some generate or guide magnetic fields, and others provide structural support or flexibility.

A research team at MIT is trying to bring 3D printing and functional hardware design together. In a paper published last month in Virtual and Physical Prototyping, the group introduced a multimaterial 3D-printing system capable of producing a working electric linear motor in about three hours. The platform processes five functional materials used in the printed motor, including conductors, magnetic structures, and flexible components.

The motor required about US $0.50 in raw materials, with the researchers positioning the platform as a way to make hardware engineering cheaper, faster, more local, and less vulnerable to supply chain disruptions. Conventional electric motors are typically assembled from separately manufactured components using multiple fabrication steps. The MIT system, however, prints the functional structures directly in one build process, with only a single post-print step to magnetize the motor’s hard magnetic parts.

The researchers started with a demo of a working linear motor—an actuator that produces smooth motion in a straight line. Eventually, they hope to scale the concept to more complex rotating motors used in vehicles and other heavy-duty applications.

How Multimaterial 3D Printing Works

3D printing has evolved significantly from its origins in rapid prototyping, but most printers operating today are still single-material, single-nozzle machines optimized for plastics. Even systems marketed as “multi-material” often mean “multi-color,” using the same underlying polymer rather than fundamentally different materials. Many extrusion-based printers swap between two similar feedstocks, such as filament, rather than combining distinct functional materials.

Most 3D printers are designed to produce plastic parts, such as prototypes, housings for electronics, or decorative objects. Building a working electric machine is far more complicated. Unlike a typical plastic print, devices like motors need different regions to do different jobs: some conduct electricity, others insulate it, some generate or guide magnetic fields, and others provide structural support or flexibility.

A research team at MIT is trying to bring 3D printing and functional hardware design together. In a paper published last month in Virtual and Physical Prototyping, the group introduced a multimaterial 3D-printing system capable of producing a working electric linear motor in about three hours. The platform processes five functional materials used in the printed motor, including conductors, magnetic structures, and flexible components.

The motor required about US $0.50 in raw materials, with the researchers positioning the platform as a way to make hardware engineering cheaper, faster, more local, and less vulnerable to supply chain disruptions. Conventional electric motors are typically assembled from separately manufactured components using multiple fabrication steps. The MIT system, however, prints the functional structures directly in one build process, with only a single post-print step to magnetize the motor’s hard magnetic parts.

The researchers started with a demo of a working linear motor—an actuator that produces smooth motion in a straight line. Eventually, they hope to scale the concept to more complex rotating motors used in vehicles and other heavy-duty applications.

How Multimaterial 3D Printing Works

3D printing has evolved significantly from its origins in rapid prototyping, but most printers operating today are still single-material, single-nozzle machines optimized for plastics. Even systems marketed as “multi-material” often mean “multi-color,” using the same underlying polymer rather than fundamentally different materials. Many extrusion-based printers swap between two similar feedstocks, such as filament, rather than combining distinct functional materials.

“Very few applications can be satisfied with just one material,” says Luis Fernando Velásquez-García, principal research scientist at MIT Microsystems Technology Laboratories, who led the study. “If you want to make hardware that actually does something well, it usually requires different materials.”

Velásquez-García argues multimaterial extrusion is the best approach for producing functional hardware. In MIT’s prototype, the printer can switch between four tools to handle feedstocks with very different properties: a heater for curing ink, a filament extruder, a custom ink extruder, and a modified pellet extruder.

The pellet-based extrusion tool is particularly useful because it allows higher magnetic particle concentrations. In standard filament printing, material is fed as a thin plastic strand, which limits how many particles can be mixed into the polymer before the filament becomes brittle. Pellet extrusion instead feeds the printer small plastic pellets, allowing much higher particle loading and improving the magnetic performance of printed components.

Velásquez-García emphasized the use of capable materials, not just printable ones. Many limitations of printed devices stem from the underlying materials used to fabricate them. If the base material’s fundamental properties fall short, performance will suffer. “You shouldn’t make any compromises in materials and performance. If you need something with optical clarity, for example, it has to be very clear or it won’t work,” Velásquez-García says. “The goal [...] should be to deliver hardware that does what people want. And if the products can be made with printing, that’s great.” He adds that, done properly, “multimaterial 3D printing is actually a win-win situation.”

Although material variety matters a lot, so does process compatibility. For example, conductive inks often need specific curing conditions to avoid damaging the insulating materials. And even if each material can be printed, the device only works if every layer aligns precisely. According to MIT, the team addressed this with a strategic sensor setup and control system so the robotic arms can interchange tools consistently and predictably.

MIT’s multi-material system can switch between four tools: (clockwise from top left) a filament extruder, pellet extruder with custom 3D-printed parts, heater for ink curing, and custom-built ink extruder

A 3D-Printed Linear Motor

For its demonstration, the MIT team focused on a linear motor, a device commonly used in high-precision systems like chip wafer manufacturing, pick-and-place robotics, medical imaging, and conveyance systems. These motors also provide a useful proving ground for printed electromagnetics.

Velásquez-García said the prototype system was built from a mix of off-the-shelf components and custom parts, and it cost “on the order of a few thousand dollars.” The platform prints linear motors using five functional material classes: dielectric, electrically conductive, soft and hard magnetic, and flexible.

The researchers reported that the printed motor performed comparably or better than devices built through conventional multi-step fabrication methods, while requiring only a single step after the print to magnetize the motor. They also said it could produce more actuation than typical linear systems that generate force through hydraulic amplifiers.

Still, this shouldn’t be mistaken for a printed EV drivetrain. The team’s next target is a more complex class of device: rotating motors. Those systems place harsher constraints around coil density, thermal management, and mechanical durability. Electric vehicles are one example of where such motors are used, but Velásquez-García stressed that the research is still far from that scale.

“There’s a long way between what we have and a 3D-printed engine in an electric car,” Velásquez-García says. “We’re far from that because we would need to make something that rotates and can deal with the temperature, load, and other things. So I think it’s exciting, but I don’t want to oversell it. It’s research and there are still a number of things that we can do, but I think it’s exciting because it’s the first of its kind.”

The team’s next goals include incorporating magnetization directly into the printing process, expanding the system with additional tools, and eventually demonstrating fully 3D-printed rotary motors—steps toward producing more complex electronic systems on a single platform.

Velásquez-García says the full system could allow engineers to combine dissimilar materials in a single print to build functional electromechanical designs remotely, far from manufacturing hubs. The long-term value is that a repair team, a remote station, or a small manufacturer could eventually fabricate specialized components without waiting on global logistics.