Roll-to-roll laser-induced superplasticity, a new fabrication method, prints metals at the nanoscale needed for making electronic devices ultrafast. Credit: Purdue University image/Ramses Martinez
A new process combining existing manufacturing tools with enhanced speed and precision could help produce faster electronics. Researchers from Purdue University have created a new manufacturing process to produce the smoother and more flexible metals required to make ultrafast electronic devices.
The new method—called roll-to-roll laser-induced superplasticity—uses a rolling stamp similar to what is used to print newspapers at high speed.
The researchers applied high-energy laser shots to different metals to induce the ultrahigh-strain-rate deformation of metallic films at room temperature into low-cost polymeric nanomolds. This enables the metal to flow into the nanoscale features of the rolling stamp while 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 nanostructures capable of interacting with light and generating 3D images, as well as the cost-effective fabrication of more sensitive biosensors,” Martinez said.
Electronic devices like cellphones, laptops and tablets all rely on metallic circuits to process information at high speeds. Current metal fabrication techniques tend to make the circuits with a thin rain of liquid metal drops that pass through a stencil mask in the shape of a circuit.
“Unfortunately, this fabrication technique generates metallic circuits with rough surfaces, causing our electronic devices to heat up and drain their batteries faster,” Ramses Martinez, assistant professor of industrial engineering and biomedical engineering, said in a statement.
However, as technology evolves, future devices will require significantly smaller metal components and a higher resolution to make them at a nanoscale size.
“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.”
The researchers were able to overcome the roughness and low-resolution limitations with the new method, which enables smooth metallic circuits to form at the nanoscale by using conventional carbon dioxide lasers.
“Printing tiny metal components like newspapers makes them much smoother,” Martinez said. “This allows an electric current to travel better with less risk of overheating.”
The study was published in Nano Letters.
