A novel method of circuit board production could lead to a new generation of faster, smaller and more energy-efficient computers.
The new production method relies on graphene, a single-atom-thick, honeycomb-shaped carbon compound that has tantalized scientists for years with electric properties that make it a promising replacement for the silicon in current computer chips. Unfortunately, producing actual electrical components from graphene has proven prohibitively expensive and difficult.
Writing in the June 11 issue of the journal Science, researchers detailed how they circumvented many of these problems by using a heated atomic microscope to create graphene on wafers of a related material.
“We used very long sheets of graphite oxide. When you heat it, it reduces back to graphene,” said Paul Sheehan, head of the surface nanoscience and sensors section at the Office of Naval Research, and lead author on the new paper. “The beauty here is you can write circuits anywhere you want.”
This new technique involves carving graphene channels out of graphite oxide wafers. The heated tip of an atomic microscope can knock the oxygen atoms off the top of the wafer, leaving pure, electrically conductive, graphene in its wake.
Previously, scientists had to assemble any graphene electrical components from loose ribbons of graphene. Aside from being a tedious, inexact and difficult process, the graphene itself is also expensive.
The process simplifies assembly by using a relatively inexpensive starting material, and by utilizing a scalable process that could easily apply to industrial-sized production lines.
By shaping graphene, scientists can turn this single material into circuits, transistors or any other component needed to make a computer chip. In current chips, silicon needs metals and other materials to produce a functioning computer part.
And while the graphene channels carved into the graphite oxide serve as the electrical components of the chip, the remaining graphite oxide also helps by insulating the graphene circuitry, and by providing a chemical anchor for sensors and other additions to the chip.