Almost all aspects of modern life, such as communications and healthcare, depend on microelectronic devices. The demand for more powerful, smaller technology keeps growing, meaning that the tiniest devices are now composed of just a few atoms. One way to solve the problem of making electronic circuits smaller is to make them more flexible so they can serve one purpose and then be completely reconfigured for another purpose.
Researchers developed a new way to create extremely thin electrically conducting sheets through nanotechnology. The team created 2D sheets, called domain walls, that exist within crystalline materials. The sheets are almost as thin as 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 means that in the future, even smaller electronic devices could be created, since electronic circuits could constantly reconfigure themselves to perform a difnumber of tasks, rather than just having one function.
The technique is similar to the popular Etch A Sketch®. In this case, patterns of electrically conducting wires can be drawn and then wiped away again as often as required. In this manner, 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.
The different pieces of the pattern fit together in a unique way so the conducting walls are found along certain boundaries where they meet.
The researchers addressed two key hurdles to creating the 2D sheets. First, long straight walls needed to be created to effectively conduct electricity and mimic the behavior of real metallic wires. Second, it is also essential to be able to choose exactly where and when the domain walls appear, and to reposition or delete them.
To solve these problems, long conducting sheets can be created by squeezing the copper-chlorine boracite crystal at precisely the location required, using a targeted acupuncture-like approach with a sharp needle. 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 sheets can then be moved around within the crystal using applied electric fields to position them.