Holographic printer creates 3D shapes in single shot

Researchers at the University of Utah have introduced a new 3D printing method that bypasses the common issue of leaky seams found in traditional layer-by-layer printing. This innovative process utilizes a nanoscale "mask" that diffracts laser light into a holographic pattern corresponding to the desired shape, enabling the print material to solidify in a single, rapid step. The entire printing process takes approximately 20 seconds, a significant improvement over the hours often required by other laser-based additive manufacturing techniques.

Published in Nature Communications, the study details how the team, led by Professor Rajesh Menon and lab member Dajun Lin, demonstrated the capability to print multiple shapes consecutively, akin to a conveyor belt. Their experiments successfully produced microtubule assemblies with individual diameters as small as 6 micrometers. These printed structures were then tested for physical durability and their ability to transport liquids through capillary action.

The technology draws inspiration from photolithography, a process used in semiconductor manufacturing, but adapts it for three-dimensional printing. The researchers employed a substrate called SU-8, a material composed of stringy polymers that cross-link and harden upon exposure to laser light. Unexposed portions of the substrate are subsequently washed away, leaving the solidified shape.

The key innovation lies in overcoming the challenge of laser diffraction when passing through the substrate to create a 3D volume. The team devised a nanopatterned lens mask that compensates for the substrate's inherent optical distortions. This mask precisely directs the laser's energy only to the intended volume within the material, ensuring accuracy. While the current prints are described as "extended 2D" structures, with controlled length and width extended into height, the researchers are actively pursuing advancements for true three-dimensional printing.