ETH Zurich are often on the cutting edge of additive manufacturing research and their recent work is no different. Kai von Petersdorff-Campen, a doctoral student in the Department of Mechanical and Process Engineering at ETH Zürich, has just developed a method they call “Embedded magnet printing”. Most impressively, however, the method relies on FFF/FDM printing using magnetic filament.
Petersdorff-Campen showed off the capabilities of the technique by creating a prototype heart pump. The process was also awarded the first prize for prototyping from the American Society for Artificial Internal Organs (ASAIO). He stresses, however, that creating a good heart pump wasn’t the real end-goal, but rather to develop it in one workflow. Besides, many deem the magnetic material unsuitable for such medical implants.
Even Petersdorff-Campen states that it wouldn’t be a good idea. Regardless, the method is still in its infancy but it’s quite promising that the researchers can create something as complex as a heart pump in a single step. As a mechanical achievement, it is quite promising.
Creating Magnetic Filament
The method prints magnets directly into the filament, combining magnetic powder and plastic into one strand. The nozzle automatically deposits the computer-generated form along with its various components. The printed parts are then magnetized in an external field. The more magnetic powder that researchers added to the granulate mix, the stronger the magnet. However, there still needs to be a proper balance, as this results in a more brittle filament overall.
“We tested various plastics and mixes until the filaments were flexible enough for printing but still had enough magnetic force,” said Petersdorff-Campen. “Some people are already asking where they can order the material. That was not my focus, I simply wanted to show the principle.”
The method is still in its early days and has a few shortcoming to work out. The plastic heart pump, for example, took 15 hours to complete. The method will truly shine in the realms of producing electronics and automotive parts. As of now, the materials may need fine-tuning and refining to produce better speeds and functionalities. The possibilities of magnetic filaments open up doors to entirely new industries.
The results can be seen in“3D Printing of Functional Assemblies with Integrated Polymer-Bonded Magnets Demonstrated with a Prototype of a Rotary Blood Pump,”. Authors include Kai von Petersdorff-Campen, Yannick Hauswirth, Julia Carpenter, Andreas Hagmann, Stefan Boës, Marianne Schmid Daners, Dirk Penner, and Mirko Meboldt.
Featured image and video courtesy of ETH Zurich.