Graphene on toast? Edible electronics could help shield you from food poisoning

From helping detect cancer cells to acting as a kick-ass superconductor, graphene is capable of all kinds of amazing feats. But how does it taste? Believe it or not, that’s one of the questions being asked by researchers at Rice University — and the answers may turn out to be a bit more profound than you may think.

What chemist James Tour and his lab have been investigating are ways to laser graphene onto food for what may turn out to be the start of a revolution in “edible electronics.”

This laser-induced graphene (LIG) technique involves making a type of graphene foam out of tiny cross-linked graphene flakes. This can then be written onto various materials, lending ordinary foodstuffs like toast (or non-consumables like paper, cardboard, fabrics and more) some of the amazing abilities that come with graphene. The technique reportedly works extremely well on coconut shells and potato skins, due to their high level of lignin, a certain class of complex organic polymer.

“We use a technique that first converts the material into amorphous carbon, like burned toast or burned carbon, by a first laser pulse, and then a second and third pulse convert the newly formed amorphous carbon into laser-induced graphene,” Tour told Digital Trends. “The entire process takes a millisecond. We do this by defocusing the laser so that there are overlapping spots as it rides along, and the overlaps are equivalent to multiple laser pulses.”

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Jeff Fitlow/Rice University
Jeff Fitlow/Rice University

But why exactly would you want to add a superthin film of graphene onto your toast, even if it is supposedly safe to eat? According to Tour, these graphene markers could act as sensors to reveal the path that food has taken from farm to table — or even to let you know if the food is safe to eat or has a bacteria like E. coli. “If you have ever had food poisoning, one needs to say no more,” Tour said. Applying the same technique to fabrics or paper could create straightforward sensors for tracking movement.

“All of our LIG is being commercialized,” he said. “First is LIG films that kill microbes for water purification. Next [is] likely flexible electronics, next on clothes.”

A paper describing the work was published in the American Chemical Society journal ACS Nano.