Conventionally, magnets are made using an injection molding process. The whole process is fine as long you need to manufacture enough of magnets to justify building a mold. However, scientists often require only a few in particular shapes for research or sensors. Thanks to a team at Vienna University of Technology, 3D printed magnets are a reality now and can be created in any shape with varying strengths.
This demands the question that why would anyone want a magnet that is unusually shaped? The answer lies in the statement from project leader Dr. Dieter Süss; “The strength of a magnetic field is not the only factor. 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.”
Let’s say you need such a 3D printed magnet. You begin by creating a digital model on a computer. This model is then fed into a 3D printer that starts 3D printing the magnet up layer by layer. The printer doesn’t make use of a polymer directly but rather heats and ejects a mixture of 90% magnetic micro granulate filaments and 10% polymer binder. Granulate is used in an un-magnetized state and therefore the final 3D printed magnet has to be exposed to a strong magnetic field for it to become a permanent magnet.
3D printed magnet offers a number of possibilities. The possibilities are not limited to shape only. You can include different sorts of magnetic materials in one magnet. This implies that a single 3D printed magnet could offer both strong and weak magnetism. While this may not seem like much, for scientists this is a breakthrough that will allow them to tinker with magnetism even more.
A paper on this particular research of 3D printed magnets was published in the journal Applied Physics Letters.