The ease of 3D printing has begun revolutionizing how we make things, and everything from houses to drones has become the subject of a 3D printing project. Despite this, there are still things to be developed when it comes to 3D printing.
A new system has been designed that, for the first time, allows for control over both the composition and the geometry of material while an item is being printed.
Jennifer A. Lewis, who is a faculty member at the Wyss Institute for Biologically Inspired Engineering at Harvard University, developed the system.
The idea for the system came about because of the fact that for many designs and products, 3D printers need to be able to transition to different materials without any issues. For example, in order to print any electronic devices, a printer would need to be able to print any hard casing enclosing the electronics, as well as electrical circuitry using multiple different inks of varying conductivity. It would need to do all of this within one print job, switching between the different materials when it needs to without stopping.
The new multimaterial printer heads are based on active mixing technology. What this means is that a range of complex fluids are combined within the printer head, with a rotating impeller located inside a nozzle.
We have seen printers able to print electrical devices before, but these printers have struggled with switching from printing flexible materials to rigid materials to electrical circuitry without pausing the printing process. This is because previous approaches to mixing fluids were passive, with fluids converging in a single channel, where they undergo diffusive mixing. This is fine for low-viscosity fluids, but for things like gels it can pose a problem.
"Passive mixtures don't guarantee perfectly mixed materials, especially highly viscous inks," said Thomas Ober, one of the authors of the paper, which was published in The Proceedings of the National Academy of Sciences. "We developed a rational framework – and verified it experimentally – for designing active microfluidic mixers that can mix a wide variety of materials."
The new technology could be used in a huge range of projects. Electronic devices and even robots could be printed using active mixing technology.
Via: Harvard University
