Rarely a month goes by without some great engineering news from Harvard. This time around, it’s a breakthrough from the John A. Paulson School of Engineering and Applied Sciences. Researchers are looking to a new form of nozzle that rotates as it extrudes as a means of arranging short fibres into much stronger structures for objects. They have named the method rotational 3D printing.
Essentially the team devised a means of programming fiber orientation with epoxy composites with locational accuracy. This then allowed them to create structures with superior stiffness, strength and durability. The unique way the nozzle moves is key to this finding.
“Rotational 3D printing can be used to achieve optimal, or near optimal, fiber arrangements at every location in the printed part, resulting in higher strength and stiffness with less material,” according to Brett Compton, co-author of the study detailing the technique. “Rather than using magnetic or electric fields to orient fibers, we control the flow of the viscous ink itself to impart the desired fiber orientation.”
The rotation of the nozzle layers the objects in such a way that it mimics the hierarchical patterns seen in nature. It also allows new arrangements that can adjust the level of stress tolerance and different points in a print.
Potential Implications of the Discovery
Aside from stronger and durable structures, there are other benefits to this style of printing. As mentioned earlier, it allows for more control over how strength and durability are spread across objects. This would in turn allow for the creation of objects with precisely controlled strength and stress points.
It can also be a potential aid in the creation of biological composites. After all, control of fiber orientation at small scales and the local level has been an obstacle to printing these composites. The method apparently also reduces material wastage.
Even though they tested it with a very specific arrangement, the team are confident that their method can be applicable to any material extrusion-based printing method, from FFF, to direct ink writing, to large-scale thermoplastic additive manufacturing, and can process any filler material, from carbon and glass fibers to metallic or ceramic whiskers and platelets.
The research is fairly new but holds promise. In given time, the idea might just become a household concept. It has potential uses everywhere, especially in the manufacturing of load-bearing objects.
