MIT: Researchers 3D print electric motor in one piece

A research team at the Massachusetts Institute of Technology (MIT) has developed a 3D printing platform that can also process various electrically conductive materials. With it, they printed a complete electric linear motor in one piece within a few hours.

The scientists used an existing multi-material 3D printer that can process two different materials with one extruder. They equipped the 3D printer with four additional extruders, each capable of processing a different material. The extruders were carefully matched to the respective material. The researchers considered the specific temperature for processing the material, material limits, and material hardness. For example, to print electrically conductive material layer by layer, it must cure without strong heat or UV light for convenient processing and without affecting the dielectric material.

Electrically conductive inks were used. However, they place completely different demands on the extruder than, for example, filament or granules, both of which are melted and pushed through a nozzle to build up the individual layers of the 3D object.

“There were significant technical challenges. We had to figure out how to seamlessly combine different variations of the same printing process – extrusion – into one platform,” explains Luis Fernando Velásquez-García, senior scientist at MIT's Microsystems Technology Laboratories (MTL) and lead author of the study “Fully 3D-Printed Electric Motor Manufactured via Multi-Modal, Multi-Material Extrusion,” which was published in Virtual and Physical Prototyping.

Precise Printhead Positioning

The MIT scientists developed a precisely operating system for controlling the printheads. Together with strategically placed sensors, it ensures that the printheads are moved to the exact desired position and deposit their material there. This ensures that each material layer is precisely aligned. This is important, as even small deviations can impair the function and performance of a printed electric motor or other machine.

After various optimization work on the 3D printer, the researchers printed a linear motor, which, unlike a rotary motor, generates linear motion. After printing, only the hard magnetic materials had to be magnetized to make the motor function. The entire printing process took only about three hours.

Material costs per component are about 50 US cents. The MIT scientists state that the printed linear motor is said to have a multiple of the drive power compared to conventionally manufactured motors of similar size.

(olb)