Researchers at Caltech have developed a 3D printing technique for creating metal nanostructures with significantly greater strength than their macroscopic counterparts.
The method utilizes a light-sensitive hydrogel that is laser-hardened and impregnated with metal ions.
This technology could find applications in the production of catalysts, electrodes, and other nanotechnological devices.
New Technique Allows 3D Printing of High-Strength Metal Nanostructures.
Researchers at the California Institute of Technology (Caltech) have made significant progress in the field of 3D printing, developing a technique that allows them to create metal nanostructures as small as 150 nanometers, which is comparable to the size of a flu virus.
These structures have three to five times greater strength than their macroscopic counterparts. The discovery, published in the journal "Nano Letters," opens new perspectives for the development of nanosensors, heat exchangers, and other nanotechnological devices.
The lead author of the study, Wenxin Zhang, explains: "At the atomic level, these nanomaterials have a very complex microstructure. At the macroscopic level, such atomic disorder would lead to significant defects and make materials weak and of poor quality. However, at the nanoscale, this disorder becomes an advantage, increasing the strength of the material."
Nanomaterial technology works with a light-sensitive mixture containing a hydrogel, which is then laser-hardened to create a 3D framework in the shape of the desired metal objects. In this study, the objects were a series of micropillars and nanogrids. The hydrogel parts are then impregnated with an aqueous solution containing nickel ions.
Once the pieces are saturated with metal ions, they are fired until the hydrogel burns out. The parts remain in the same form as the original, but reduced and made entirely of metal ions that are now oxidized (bonded to oxygen atoms). In the final step, oxygen atoms are chemically removed from the parts, converting the metal oxide back to its metallic form.
This process of 3D printing nanoscale metal structures could have applications in making a variety of useful components, including catalysts for hydrogen, electrodes for storing ammonia and other carbon-free chemicals, and key parts of devices such as sensors, microrobots, and heat exchangers, according to Julia R. Greer, professor of materials science, mechanical engineering, and medical engineering at Caltech and head of the laboratory where the study was carried out.
This discovery highlights the unusual properties of matter at the nanoscale and heralds a revolution in the development of nanotechnological devices. "Physics at the nanoscale is really strange, and the deeper we delve into this world, the more often we come across unusual laws," concludes Zhang.
This is a reminder that science and technology are constantly evolving, opening up new opportunities for the use of nanomaterials in various fields, from medicine to space exploration.
