Jan 24, 2020 | |
Nano-thin flexible touchscreens could be printed like newspaper(Nanowerk News) Researchers have developed an ultra-thin and ultra-flexible electronic material that could be printed and rolled out like newspaper, for the touchscreens of the future. |
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The touch-responsive technology is 100 times thinner than existing touchscreen materials and so pliable it can be rolled up like a tube. | |
To create the new conductive sheet, an RMIT University-led team used a thin film common in cell phone touchscreens and shrunk it from 3D to 2D, using liquid metal chemistry. | |
The nano-thin sheets are readily compatible with existing electronic technologies and because of their incredible flexibility, could potentially be manufactured through roll-to-roll (R2R) processing just like a newspaper. | |
The research, with collaborators from UNSW, Monash University and the ARC Centre of Excellence in Future Low-Energy Electronics Technologies (FLEET), is published in the journal Nature Electronics ("Flexible two-dimensional indium tin oxide fabricated using a liquid metal printing technique"). | |
A sample of the ultra-thin and ultra-flexible electronic material that could be printed and rolled out like newspaper, for the touchscreens of the future. (Image: RMIT University) | |
Lead researcher Dr Torben Daeneke said most cell phone touchscreens were made of a transparent material, indium-tin oxide, that was very conductive but also very brittle. | |
"We've taken an old material and transformed it from the inside to create a new version that's supremely thin and flexible," said Daeneke, an Australian Research Council DECRA Fellow at RMIT. | |
"You can bend it, you can twist it, and you could make it far more cheaply and efficiently that the slow and expensive way that we currently manufacture touchscreens. | |
"Turning it two-dimensional also makes it more transparent, so it lets through more light. | |
"This means a cell phone with a touchscreen made of our material would use less power, extending the battery life by roughly 10%." | |
DIY: a touchscreen you can make at home |
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The current way of manufacturing the transparent thin film material used in standard touchscreens is a slow, energy-intensive and expensive batch process, conducted in a vacuum chamber. | |
"The beauty is that our approach doesn't require expensive or specialised equipment - it could even be done in a home kitchen," Daeneke said. | |
"We've shown its possible to create printable, cheaper electronics using ingredients you could buy from a hardware store, printing onto plastics to make touchscreens of the future." | |
Thick and thin: how to turn an old material new |
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To create the new type of atomically-thin indium-tin oxide (ITO), the researchers used a liquid metal printing approach. | |
An indium-tin alloy is heated to 200C, where it becomes liquid, and then rolled over a surface to print off nano-thin sheets of indium tin oxide. | |
These 2D nano-sheets have the same chemical make-up as standard ITO but a different crystal structure, giving them exciting new mechanical and optical properties. | |
As well as being fully flexible, the new type of ITO absorbs just 0.7% of light, compared with the 5-10% of standard conductive glass. To make it more electronically conductive, you just add more layers. | |
It's a pioneering approach that cracks a challenge that was considered unsolvable, Daeneke said. | |
"There's no other way of making this fully flexible, conductive and transparent material aside from our new liquid metal method," he said. | |
"It was impossible up to now - people just assumed that it couldn't be done." | |
Patent pending: bringing the tech to market |
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The research team have now used the new material to create a working touchscreen, as a proof-of-concept, and have applied for a patent for the technology. | |
The material could also be used in many other optoelectronic applications, such as LEDs and touch displays, as well as potentially in future solar cells and smart windows. | |
"We're excited to be at the stage now where we can explore commercial collaboration opportunities and work with the relevant industries to bring this technology to market," Daeneke said. |
Source: RMIT University | |
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