Though printed newspapers may one day become a thing of the past, researchers are taking inspiration from the process used to print them to create a new product: electronic devices. Researchers at Purdue University have developed a manufacturing technique that uses a process akin to newspaper printing for the formation of smoother and more flexible metals. They believe the low-cost process can form the basis for fabricating ultra-fast electronic devices, said Ramses Martinez, assistant professor of industrial engineering and biomedical engineering at the university, in a Purdue news release.
|Roll-to-roll laser-induced superplasticity, a new fabrication method developed by researchers at Purdue University, prints metals at the nanoscale needed for making electronic devices ultra-fast. (Image source: Purdue University/Ramses Martinez)|
Devices like smartphones, laptops, and other electronics can only process information at a high speed due to internal metallic circuitry. Currently, these circuits are typically made by passing a thin rain of liquid metal drops through a stencil mask in the shape of a circuit—a technique similar to spraying graffiti on walls. The problem with this technique, however, is that it “generates metallic circuits with rough surfaces, causing our electronic devices to heat up and drain their batteries faster,” Martinez said.
He and his team think the process they developed solves this issue. It combines tools already used in industry for manufacturing metals on a large scale with the speed and precision of roll-to-roll newspaper printing, Martinez said.
The process removes fabrication barriers that currently exist, paving the way for electronics that are faster than they are today. For speed, they require smaller metal components, which will require a high resolution for fabricating them at the nanoscale sizes needed for ultra-fast electronics, he said. "Forming metals with increasingly smaller shapes requires molds with higher and higher definition, until you reach the nanoscale size," Martinez said. "Adding the latest advances in nanotechnology requires us to pattern metals in sizes that are even smaller than the grains they are made of. It's like making a sand castle smaller than a grain of sand."
Roll to Roll
The process developed by the Purdue team—called roll-to-roll laser-induced superplasticity—allows for this by using conventional carbon dioxide lasers, which are already common for industrial cutting and engraving. It enables the fabrication of nano-scale metal components that are both smooth and have a high resolution, Martinez said: "Printing tiny metal components like newspapers makes them much smoother. This allows an electric current to travel better with less risk of overheating.”
Specifically, the process uses a rolling stamp like the ones used to print newspapers at high speed, researchers said. The technique can induce, briefly, "super-elastic" behavior to different metals by the application of high-energy laser shots, Martinez explained. This enables the metal to flow into the nanoscale features of the rolling stamp, allowing the desired result.
The team envisions that this type of fabrication of electronic devices will pave the way for applications like touchscreens covered with nanostructures capable of interacting with light and generating 3D images, Martinez said. It also will make the fabrication of highly sensitive biosensors more cost-effective. Researchers published a paper on their work in the journal Nano Letters.
Elizabeth Montalbano is a freelance writer who has written about technology and culture for 20 years. She has lived and worked as a professional journalist in Phoenix, San Francisco and New York City. In her free time she enjoys surfing, traveling, music, yoga and cooking. She currently resides in a village on the southwest coast of Portugal.
|Today's Insights. Tomorrow's Technologies.
ESC returns to Minneapolis, Oct. 31-Nov. 1, 2018, with a fresh, in-depth, two-day educational program designed specifically for the needs of today's embedded systems professionals. With four comprehensive tracks, new technical tutorials, and a host of top engineering talent on stage, you'll get the specialized training you need to create competitive embedded products. Get hands-on in the classroom and speak directly to the engineers and developers who can help you work faster, cheaper, and smarter. Click here to register today!