The shine in gold has always attracted us. Now, it has a new use in finding defects in 3D printing, new research suggests. This is for the first time, scientists at the Vanderbilt University have demonstrated a new application of gold in finding faults.
Scientists have developed a technique for gold to that will highlight the problem in 3D printing once got inside.
Cole Brubaker, civil engineering graduate student, and lead author of the study said, “We are able to inspect and detect defects that aren’t visible to the naked eye, using the optical properties of embedded gold nanoparticles. That’s a very critical step – being able to say ‘We have a defect. It’s right here.”
Kane Jennings, chair and professor of chemical and biomolecular engineering and co-author on the paper said, “Sometimes, there can be a problem inside 3D printed parts. Small defects or missing print layers can occur. These defects can compromise and weaken the structural integrity of the 3D printed products, causing failure.”
Researchers utilized super-small particles of gold, which really appear as a profound maroon color. The nanoparticles are around 100,000 times thinner than a human hair, yet they could solve a noteworthy issue in assembling.
Scientists then decided to embed gold inside the printing material to see whether it could help flag those defects. The system highlights the problem with one single nondestructive measurement within a matter of seconds.
The process originally involves merging of the gold nanoparticles with a dissolved plastic polymer, scattering it all through the medium. When it dries and solidifies, the plastic is expelled or squeezed into gold nanoparticle-filled polymer fibers, or thin tubing, which would then be able to be utilized as a part of standard 3D printers.
After a part is printed, it goes into an especial UV-Vis spectrophotometer to examine for defects.
Brubaker said, “We’re using the absorbance properties of the embedded gold nanoparticles. You just scan light across the surface of the sample and see where the absorbance decreases inside, signaling a defect in that material. A defect can be found with one single nondestructive measurement. It’s very quick. It takes just a matter of seconds. We don’t have to rely on large sensing systems that have sensors placed all over the part.”
Jennings said, “There are tremendous possibilities for what we can do with this technology. We have demonstrated the 3D printed parts can be self-reporting. They self-report defects. We’re looking now at the possibility to do even more with these smart materials.”
The interdisciplinary team included researchers from the departments of civil and environmental engineering, chemical and biomolecular engineering and chemistry, along with help from an undergraduate student studying at Fisk University in Nashville. The research was funded by the U.S. Office of Naval Research. Patents are pending on the technology and the research findings have been published in the American Chemical Society Applied NanoMaterials Journal.