Researchers are developing a light-based way to print nanoscale structures

Researchers at the Georgia Institute of Technology have developed a new light-based way to print nanoscale structures that is significantly cheaper and faster than current technology. The discovery has the potential to bring new technologies from the lab to mass production.


Assistant Professor Saurabh Saha and Ph.D. Jungho Choi, a student in the George W. Woodruff School of Mechanical Engineering, has developed a technique for printing metal nanostructures that is 480 times faster and 35 times cheaper than current methods.


The findings are published Advanced Materials magazine. Saha and Choi's scalable solutions will replace existing technologies that are expensive and slow.


The development of electronic devices, sensors, solar energy conversion and other systems relies on nanopatterning, which creates unique structures that are printed on nanoscale metal. The technique uses high-intensity light sources, with a femtosecond laser costing up to half a million dollars.


Saha and Choi looked for a low-cost, low-intensity light that works like a femtosecond laser. They chose superluminescent light-emitting diodes (SLEDs), which emit billions of times less light than femtosecond lasers and are also commercially available.


„As a scientific community, we lack the ability to make these nanomaterials quickly and cheaply, which is why promising technologies are often limited to the laboratory and never translate into real-world applications,” explained Saha. .


The pair developed an original projection-style printing technology that converts digital images into optical images and displays them on a glass surface. Although operating like digital projectors, the computer produces images that are more sharply focused. They were able to use the unique properties of superluminescent light to create sharp images with minimal defects.


Then they created a clear ink solution that could absorb light with a metal salt and other chemicals. When the light from the projection system hit the light, a chemical reaction occurred that turned the salt solution into metal. The metal nanoparticles adhered to the surface of the glass and the aggregation of the metal particles formed the nanostructure.


Because of the projection type printing, this system can print an entire structure at once rather than point by point. Saha and Choi say their technique could be useful for people working in fields that require various complex metal nanostructures, such as electronics, plasmonics and optics.


„Currently, only top universities have access to these expensive technologies, and they are located in shared facilities and are not always available. We want to democratize the potential of nanoscale 3D printing, and we believe our research will open the door to greater access to such processes at low cost,” said Choi. .


The technique was tested with low-intensity light, however, it proved successful only if the images were in sharp focus. Saha and Choi hope the researchers can replicate their work using commercially available hardware. The SLED type used in their printer costs around $3,000.


„I think the metrics of cost and speed are greatly underestimated in the scientific community working on developing and manufacturing small structures,” Saha said. „In the real world, these metrics are important when translating discoveries from the lab to industry. Only if we have manufacturing techniques that take these metrics into account can nanotechnology be fully exploited for societal benefit.