Phone screens flattened for new tech
Australian researchers have developed an ultra-thin and ultra-flexible electronic material that can be printed and rolled.
The touch-responsive technology is 100 times thinner than existing touchscreen materials and so pliable it can be rolled into a tube.
The new conductive sheet is made from a thin film common in mobile phone touchscreens, only in this case it has been shrunk 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.
It uses indium-tin oxide, a transparent material that most mobile phone touchscreens are made of, which is 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 lead researcher Dr Torben Daeneke.
“You can bend it, you can twist it, and you could make it far more cheaply and efficiently than 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 mobile phone with a touchscreen made of our material would use less power, extending the battery life by roughly 10 per cent.
“The beauty is that our approach doesn’t require expensive or specialised equipment – it could even be done in a home kitchen.
“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.”
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 per cent of light, compared with the 5-10 per cent of standard conductive glass. To make it more electronically conductive, more layers can be added.
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,” Dr Daeneke said.