First 3D printer that can make magnets
Image credit: TU Wien
Austrian researchers have developed a 3D printer that can make customisable magnets with precisely engineered magnetic fields.
While making strong permanent magnets is quite simple with today’s manufacturing methods, fine-tuning the magnetic field is much more complicated.
Previous methods required magnets of pre-defined shapes to be created using moulds, which is time-consuming, costly and only worthwhile for larger batches of magnets.
“We often require special magnetic fields, with field lines arranged in a very specific way - such as a magnetic field that is relatively constant in one direction, but which varies in strength in another direction,” explained Dieter Süss, from the Vienna University of Technology, who led the team developing the printer.
The researchers said that thanks to the technology, making magnets with exactly defined magnetic fields would be much simpler.
The 3D printer is the first ever that can produce magnetic materials. It works similarly to standard 3D printers that make plastic structures but uses special filaments of magnetic micro-granulate held together by a polymer binding material.
The printer heats the material and applies it point by point in the desired locations based on a computer design. The result is a three-dimensional object composed of roughly 90 per cent magnetic material and 10 per cent plastic.
“A magnet can be designed on a computer, adjusting its shape until all requirements for its magnetic field are met,” said Christian Huber, a doctoral student in Dieter Süss’s team.
The object is initially not magnetic and has to be exposed to a strong magnetic field that converts it into a permanent magnet.
“This method allows us to process various magnetic materials, such as the exceptionally strong neodymium iron boron magnets,” Süss said. “Magnet designs created using a computer can now be quickly and precisely implemented - at a size ranging from just a few centimetres through to decimetres, with an accuracy of well under a single millimetre.”
The technique allows creating magnets that combine various different materials. Such a magnet could, for example, have a strong magnetic field on one end and a weak one on the other end.
“Now we will test the limits of how far we can go - but for now it is certain that 3D printing brings something to magnet design which we could previously only dream of,” Süss concluded.