The intersection of light beams is the key to the transformative potential of the 3D printer
QUT researchers have used crossed beams of light to control chemical reactions in an advanced material, paving the way for future use in 3D printers that print entire layers, instead of single dots, at once.
QUT’s Center for Materials Science interdisciplinary research team, consisting of Dr Sarah Walden, Leona Rodrigues, Dr Jessica Alves, Associate Professor James Blinco, Dr Vinh Truong and ARC Laureate Professor Christopher Barner-Kowollik , published his research in Nature Communications.
Dr. Walden said light was a particularly desirable tool for activating chemical processes, because of the precision it offered for starting a reaction.
“Most of the work that QUT Soft Matter Materials Group researchers have done in the past with light has involved using a laser beam to start and stop a chemical reaction across the entire volume where the light hits the material. “, said Dr. Walden.
“In this case, we have two light beams of different colors, and the reaction only occurs at the intersection of the two beams.
“We use one color of light to activate one molecule and the second color of light to activate another molecule. And where the two light beams meet, the two activated molecules react to form a solid material.
“Normally, in a 3D printer, the inkjet moves in two dimensions, slowly printing a 2D layer before coming up to print another layer on top.
“But using this technology, you can activate an entire two-dimensional sheet and print the entire sheet at once.”
Professor Barner-Kowollik said such two-color activated materials are currently very rare.
“This project aims to prove the ink’s viability for the future generation of printers,” he said.
Professor Barner-Kowollik, whose career has focused on the power and possibilities of light in materials science, was recently honored with Australia’s highest award for chemistry, the 2022 David Craig Medal, awarded by the Australian Academy of Sciences.
Professor Barner-Kowollik said one of the challenges of the project was to find two molecules that could be activated by two different colors of light and then make them react together.
“That’s where the innovation comes from,” Professor Barner-Kowollik said.
“You want a molecule to be activated with one color of light but not with the other color, and vice versa.
“It’s not easy to find, it’s actually quite hard to find.”
Dr. Truong, after much work, was able to find two molecules that reacted to lights in the required way and combined to form a very strong material.
“In our chemical design, both light-activated processes are reversible,” Dr Truong said.
“So we can control exactly when and where solid material can form.”
The researchers are from the QUT School of Chemistry and Physics.