A screen that can quickly sustain damage that is difficult to repair. Batteries that lose the ability to sustain a charge over time.
These are some of the unfortunate issues that can occur with the current crop of smartphones.
However, two new studies propose novel techniques for improving these features by harnessing the properties of graphene.
Scientists from the University of Sussex devised a method that could yield new smartphone touch screens that are more durable than previous iterations.
Indium tin oxide is the current element used to manufacture phone screens. The indium component is a rare metal that can be ecologically damaging to extract. Silver has been viewed as the best alternative to indium tin oxide, but is also expensive.
The researchers from the University of Sussex were able to create a new hybrid material comprised of silver nanowires and graphene, by gathering a layer of graphene atoms and placing them on top of the silver nanowire in a pattern.
The end result is a ‘stamp’ made from poly(dimethyl siloxane), which is the same kind of silicone rubber used in kitchen utensils and medical implants.
“While silver nanowires have been used in touch screens before, no one has tried to combine them with graphene. What’s exciting about what we’re doing is the way we put the graphene layer down. We float the graphene particles on the surface of water, then pick them up with a rubber stamp, a bit like a potato stamp, and lay it on top of the silver nanowire film in whatever pattern we like. “And this breakthrough technique is inherently scalable. It would be relatively simple to combine silver nanowires and graphene in this way on a large scale using spraying machines and patterned rollers. This means that brittle mobile phone screens might soon be a thing of the past,” said Professor Alan Dalton from the school of Maths and Physical Science at the University of Sussex, in a statement.
Essentially, this ‘potato-stamp’ technique yielded a new material that is cheaper, less brittle, and more environmentally friendly.
Findings from this study appeared in the journal Langmuir.
Better battery charging
Engineers at the University of Waterloo explored how adding graphene could boost the performance of supercapacitors, which are considered to be a promising green alternative to traditional batteries. Some of the proposed benefits of this power source include faster charging and better safety and reliability.
One drawback is that these machines have relatively low storage capacities. Existing supercapacitors can only retain energy for about 10 percent as long as rechargeable batteries.
The team of scientists from the University of Waterloo found a way around this issue, by coating atomically thin layers of graphene with an oily liquid salt in supercapacitor electrodes.
Adding the salt to this mixture served two crucial roles.
The first was that it acted as a spacer to separate the thin graphene sheets, dramatically increasing its exposed surface area and therefore maximizing the energy-storage function. Also, the salt served as the electrolyte needed to actually store the electrical charge, reducing the size and weight of the supercapacitor.
Ultimately, this novel design was able to roughly double the amount of electrical energy that the rapid-charging devices can hold, potentially becoming convenient and reliable power sources for a number of consumer devices, including laptops and smartphones.