Researchers at TU Wien wanted to create magnets with exactly the right magnetic field for a particular application. Their solution? 3D printing of magnets. Previously, it has been difficult to produce permanent magnets with a specific shape of the magnetic field. The resulting magnets will be a boon to magnetic sensor construction.
Previously, after designing a magnet with a specific shape and magnetic field, a researcher would have to create tooling for injection molding. This is expensive and time-consuming and often not worth it for small quantities of magnets.
The new technique uses filament that contains magnetic microgranules. The filament is about 10% plastic and 90% magnetic material. While it is in the filament (and in the printer), the material is not magnetized. At the end of the print, a strong magnetic field magnetizes the finished product.
In addition to customized shapes, the printed material may open up other possibilities such as using different materials in a single magnet to create strong and weak regions.