A team of MIT and University of Michigan researchers has a new method for manufacturing graphene that it believes could take the material out of the laboratory and into commercial products. The method involves forming the strong, conductive material in a chamber consisting of two concentric tubes.
Graphene is a material with some serious potential. It's strong, highly conductive and could be used in solar panels, flexible light sources and more. Unfortunately, it's also rather difficult to fabricate, with most existing solutions unable to produce patches of the material large enough for widespread commercial uses.
A new technique pioneered by MIT researchers could make things significantly easier. It's similar to the existing chemical vapor deposition method, but makes use of a chamber consisting of two concentric tubes – one placed inside the other. The technique requires the chamber to be heated to around 1,000 °C (1,832 °F).
The substrate on which the graphene forms is wound around the inner tube, with gases flowing through the larger tube and out of a set of holes halfway along the inner tube. This allows the process to be split into two stages, with the first part of the chamber used to prepare the substrate, and the second used to grow the graphene upon it.
The MIT team built and tested a lab-scale version of the chamber, finding that when the substrate is moved through at a pace of 25 mm (1 in) per minute, a high-quality, uniform layer of graphene is formed. Turning up the speed to 50 cm (20 in) a minute produces a lower-quality coating that would still be useable for certain applications. The researchers claim that the technique is scalable, with the resulting graphene samples only limited by the width of the rolls of foil and the size of the chamber used.
This isn't the first time we've seen an innovative technique for making graphene come out of MIT. Back in May 2014, the same collaborative team detailed a method that allows for the formation of the material on both sides of a film, binding it directly to a substrate. As with the new research, it's thought that the technique could be used on a large scale.
As for the new tube-chamber method of graphene production, the team is now working to tweak the process to allow for the production of high-quality graphene layers at higher speeds, improving the potential of the technique.
The findings of the study were published in the journal Scientific Reports.
Source: MIT