This is an image of domain walls in a crystal. Image: Queen's University Belfast.
This is an image of domain walls in a crystal. Image: Queen's University Belfast.

Researchers at Queen's University Belfast in the UK have discovered a new way to create extremely thin electrically conducting sheets, which could revolutionize the tiny electronic devices that control everything from smart phones to banking to medical technology.

Through nanotechnology, physicists Raymond McQuaid, Amit Kumar and Marty Gregg from Queen's University's School of Mathematics and Physics have created unique two-dimensional (2D) sheets called domain walls that exist within crystalline materials. These sheets are almost as thin as the wonder-material graphene, at just a few atomic layers. However, they can do something that graphene can't – they can appear, disappear or move around within the crystal, without permanently altering the crystal itself.

This discovery could allow the creation of electronic circuits that constantly reconfigure themselves to perform a number of tasks, rather than just having a sole function, leading to even smaller electronic devices.

"Almost all aspects of modern life such as communication, healthcare, finance and entertainment rely on microelectronic devices," explains Gregg. "The demand for more powerful, smaller technology keeps growing, meaning that the tiniest devices are now composed of just a few atoms – a tiny fraction of the width of human hair.

"As things currently stand, it will become impossible to make these devices any smaller – we will simply run out of space. This is a huge problem for the computing industry and new, radical, disruptive technologies are needed. One solution is to make electronic circuits more 'flexible' so that they can exist at one moment for one purpose, but can be completely reconfigured the next moment for another purpose."

The team's findings, which are published in a paper in Nature Communications, offer a way to do this, potentially leading to a completely new approach to data processing. "Our research suggests the possibility to ‘etch-a-sketch’ nanoscale electrical connections, where patterns of electrically conducting wires can be drawn and then wiped away again as often as required," says Gregg.

"In this way, complete electronic circuits could be created and then dynamically reconfigured when needed to carry out a different role, overturning the paradigm that electronic circuits need be fixed components of hardware, typically designed with a dedicated purpose in mind."

Two key hurdles need to be overcome to create these 2D sheets. The first is creating long straight walls that can conduct electricity effectively and mimic the behavior of real metallic wires. The second is being able to choose exactly where and when these domain walls appear, and to reposition or delete them.

Through their research, the Queen's researchers have discovered solutions to these hurdles. Their research proves that long conducting sheets can be created by squeezing the crystal at precisely the location they are required, using a targeted acupuncture-like approach with a sharp needle. The sheets can then be moved around within the crystal using applied electric fields to position them.

"Our team has demonstrated for the first time that copper-chlorine boracite crystals can have straight conducting walls that are hundreds of microns in length and yet only nanometers thick, " says McQuaid, a recently-appointed lecturer in the School of Mathematics and Physics at Queen's University. "The key is that, when a needle is pressed into the crystal surface, a jigsaw puzzle-like pattern of structural variants, called ‘domains’, develops around the contact point. The different pieces of the pattern fit together in a unique way with the result that the conducting walls are found along certain boundaries where they meet.

"We have also shown that these walls can then be moved using applied electric fields, therefore suggesting compatibility with more conventional voltage-operated devices. Taken together, these two results are a promising sign for the potential use of conducting walls in reconfigurable nano-electronics."

This story is adapted from material from Queen's University Belfast, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.