Manufacturing Process Dispenses Medical Devices

German researchers are advancing an additive manufacturing method for creating medical tools, implants, dentures and anything else that requires multiple ingredients and a complex design. The 3D printing technique developed at Fraunhofer Institute for Ceramic Technologies and Systems IKTS works with glass, ceramic, plastic, and metals, allowing the designer to combine any of these into a single product.

The technology uses suspensions of the materials, thanks to a thermoplastic binder that is liquid at around 180°F (80°C). This allows each layer to quickly cool to room temperature and for the next one to be deposited. Powder particles of metal, glass or ceramics are dispersed within the binder; viscosity of the suspension can be regulated to optimize it for specific applications. The electrically generated temperature in the printer melts the suspension and droplets harden after deposition due to the quick cooling process. The workpiece is then built up point by point on a flat platform, allowing different materials to be deposited at the same time via multiple application units.

One area in which the multi-material approach is important is surgery: endoscopes frequently use an instrument to first cut open tissue, and then close the blood vessels using electric current. To prevent electricity from shocking the patient, the instrument not only needs high-grade steel but also insulated ceramic components.

”Ceramic substances are often well-suited for medical devices and components. Ceramics are sturdy and can be cleaned thoroughly,” says Dr. Tassilo Moritz from Fraunhofer IKTS’s Materials and Processes business division. “We can now build ceramic components that fit the application instead of the production process,” says the materials scientist. To date, ceramic microreactors have mostly been milled out of plates. Internal and external sealing, however, have presented a technological challenge for this. And there has been the problem of making connections that fit. “Now we can just print them onto the ceramic component during manufacturing in whatever form,” Moritz says.