Scientists in the McAlpine Research Group at Princeton University are developing a wireless chip that can monitor any surface for contaminants. The chip is made out of graphene, a single layer of graphite. It’s a highly conductive material that can flex & stretch without damage, and since it’s only about a nanometer thick, it strongly adheres to any surface its full area is in contact with. Additionally, because it can flex & stretch, it will stick to moving surfaces, like skin or a plastic bag. The lab has developed a pattern for the chip that is highly sensitive to the presence of contaminants (which change its electrical properties) and can wirelessly send that information to a receiver. They construct the chip like a temporary tattoo so that it can be easily applied to any surface—the graphene is printed in the necessary shape and then a backing of raw silk is attached. To apply the chip, you wet the silk, which dissolves it and leaves the graphene behind. A plain graphene chip will sense any contaminants, but they’ve also developed a more selective version. By attaching particular peptides to the graphene’s surface, the chip can selectively indicate when bacteria are present. They’re currently working on making the chip even more discerning so that it could detect certain species of bacteria. In particular, they’re looking at a chip that can be applied to a tooth to monitor for H. pylori, a bacteria that (along with a few other factors) causes stomach ulcers, and one that can be applied to medical equipment to monitor for S. aureus, which has a host of strains (including MRSA) that can be very dangerous to people. Now that the basic design is down, the applications are practically endless.
Guest article written by Kati (thescienceage.tumblr.com)