3-D printed magnets can be produced with precise magnetic field

From the technical point of view, manufacturing robust magnets is no more a big problem. It is but complicated to manufacture a permanent magnet with desired magnetic field of a specific pre-determined structure. That was the case, till now, as it has become possible with the novel solution devised at TU Wien – for the very first time ever, permanent magnets can be manufactured utilizing a 3D printer. This enables magnets to be prepared in intricate forms and accurately customized magnetic fields, needed, for instance in magnetic sensors.

 

 

 

 

 

“The strength of a magnetic field is not just the factor,” confirms Dieter Suss, Head of the Christian Doppler Advanced Magnetic Sensing and Materials Laboratory at TU Wien. “We often needed special magnetic fields with single lines organized in a highly specific manner – like themagnetic field that is relatively constant in single direction, but which differs in strength and in another direction.”

For accomplishing such needs, magnets must be prepared with a sophisticated geometric structure. “A magnet can be created on a PC, adjusting its shape till entire needs for its magnetic field are met,” explains Christian Huber, a doctoral student in Dieter Suss group.

But once you have appropriate geometric shape, how do you go about executing the design? The injection moulding procedure is a single solution, but this needs the creation of a mould, which is expensive and time-consuming, rendering this process barely worthwhile for manufacturing small proportions.

Now, there is a much simple technique – the first ever 3-D printer that can be employed to manufacture magnetic materials, prepared at TU Wien. 3D printers that release plastic structures have existed for some time, and the functions of magnet printer utilize specially manufactured filaments of magnetic micro granulate that is linked together through a polymer binding substance. The printer heats the substance and applies it step by step in the desired locations with the help of a nozzle. As a result, a 3-dimensional object made of 90% magnetic substance and 10% plastic is obtained.

“Such method enables us to process multiple magnetic substances, like the exceptionally robust neodymium iron boron magnets,” confirms Dieter Suss. “Magnet designs prepared to utilizea computer can now be precisely and quickly implemented – at a range from ajusta couple of centimetres through to decimetres with a precision rate of well under a single millimetre.”

Conclusion

The novel process is not just cost-effective and fast, it also offers new opportunities that would be inconceivable with other methods. You may use distinct substances within a single magnet to prepare a smooth transition between weak and strong magnetism. “Now we would test the limits of how far we can go, but for now it is confirmed that 3D printing brings elements to magnet design that could previously just dream of,’ says Dieter Suss.