All electronic circuits—no matter how basic—require conductive material to operate. In almost all modern electronics, that material is copper because it’s relatively abundant and easy to work with. But, that doesn’t mean copper is the only choice, or even the best choice. Graphene is far more conductive, and now it can be etched onto a wide variety of materials with just a laser thanks to scientists at Rice University.
The technique can be used on a lot of different organic materials, including cotton, paper, cork, and even food like potatoes and toast. Graphene is created on the surface of the material with just two passes of a defocused laser. The first past essentially burns the surface, which converts it into amorphous carbon. The second pass then takes advantage of the selective absorption of infrared light to convert the carbon into laser-induced graphene (LIG).
Like any other kind of laser engraving, this can be used to lay down specific patterns. In this case, those patterns can be traces of LIG that form electronic circuits. The researchers envision this being used for embedding data or expiration indicators on food itself, or for creating wearable circuits that are printed directly onto clothing.