Researchers at Purdue University have designed a new low-cost manufacturing technique to print electronic components. The new technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices. Combining tolls already used in the manufacturing industry, the technique also uses the speed and precision of roll-to-roll newspaper printing to remove a couple of fabrication barriers in making electronics faster than they are today.
Current metal fabrication techniques tend to make the internal circuits of various electronics, like cell phones, laptops and tablets, via a process where a thin rain of liquid metal drops into a stencil mask to form a circuit – much like spray painting on walls.
“Unfortunately, this fabrication technique generates metallic circuits with rough surfaces, causing our electronic devices to heat up and drain their batteries faster,” said Ramses Martinez, an assistant professor of industrial engineering and biomedical engineering in an interview with Phys.org, a science, research and technology news aggregator.
“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.”
This “formability limit” hinders the ability to manufacture materials with nanoscale resolution at high speed. Through way of a new large-scale fabrication method that enables the forming of smooth metallic circuits at the nanoscale using conventional carbon dioxide lasers, which are already common for industrial cutting and engraving, Purdue researchers have addressed both the roughness and low resolution issues.
“Printing tiny metal components like newspapers makes them much smoother. This allows an electric current to travel better with less risk of overheating,” Martinez said.
The fabrication method, called ‘roll-to-roll laser-induced superplasticity’, uses a rolling stamp like the ones used to print newspapers at high speed. The technique can induce, for a brief period of time, “super-elastic” behavior to different metals by applying high-energy laser shots, which enables the metal to flow into the nanoscale features of the rolling stamp – essentially, circumventing the formability limit.
“In the future, the roll-to-roll fabrication of devices using our technique could enable the creation of touch screens covered with nano-structures capable of interacting with light and generating 3-D images, as well as the cost-effective fabrication of more sensitive biosensors,” Martinez said.