Future iPads could be a lot cheaper thanks to research conducted by Duke and the University of Pennsylvania.
Collaboration between studies conducted by researchers from Duke and UPenn could allow metal nanowire film to be used in future touchscreen technology. Because metal nanowire film is cheaper and applied more quickly, future generations of touchscreen technology could be markedly cheaper.
“People have been making transparent conductors from metal nanowires for five or six years in the lab, maybe more,” said Karen Winey, professor of material sciences and engineering at UPenn and co-author of the study. “But they’re not great… Through his synthetic methods and our simulations, I think we’re going to be able to make faster progress to something that’s going to be commercially adopted.”
The Duke researchers—who belonged to the lab of Benjamin Wiley, assistant professor of chemistry—began by looking at the structure and properties of metal nanowire film. In particular, the researchers looked at its length and diameter to determine how these variables give rise to the nanowires’ properties.
Ultimately, Wiley’s group was able to obtain four data points for the length of the nanowires and two for the width. The limited scope of the data set, however, prevented them from generalizing the properties of nanowires’ other lengths and widths.
“We’re growing these crystals in solution,” Wiley said. “You can imagine trying to cook something where you have control of the scale of one-one thousandth of a human hair… Just like in cooking, there’s an inherent randomness, so the same thing happens when we ‘cook’ nanowires.”
Enter the Winey Lab. Before the collaboration, the Penn scientists had been working with three-dimensional composites and had begun to adjust their focus to two-dimensional simulations, an area consistent with Wiley’s work with nanowire films. Duke’s experimental data was able to validate Penn’s computational simulations.
“Professor Wiley is attacking that problem by developing new synthetic routes, new ways to synthesize metal nanowires and new ways to fabricate nanowire networks,“ Winey said. “My group has the same goal, but we’re attacking it from a different direction. We are trying to use computational methods to understand or predict what types of wires are going to have the best results.”
The partnership gave rise to a model that determined the resistance of nanowire film which will help achieve a refined understanding of metal nanowire networks.
“[Winey’s] model is, take some sticks, throw them across the floor, what is the conductivity across that network of sticks?” Wiley explained. “If you think about this sort of situation, what can you vary? We can change the number of sticks, their length and their width.”
The research could present commercial applications and reduce the price of touchscreen technology significantly.
Current touchscreen technology is very expensive because it uses indium tin oxide, a costly product, Wiley noted. The slow vapor deposition process involved in its application raises costs further. In comparison, metal nanowires are suspended in ink and then coated to surfaces, presenting a liquid coatable alternative.
In addition, ITO is fairly brittle, but metal nanowires would allow for flexible touchscreens and solar cells that use flexible conductors.
Rose Ritts, executive director of the Duke Office of Licensing and Ventures, said Duke is looking into the commercial applications of this research.
“My office is actively involved in finding a partner to commercialize [Wiley’s] technology,” she said.
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