Researchers create edible graphene tag, which can be etched onto bread

05-Mar-2018 - Last updated on 05-Mar-2018 at 13:06 GMT

Rice graphene on toast. Photo: Rice University.

Researchers at Rice University have created a way to etch a graphene ‘label’ onto food like bread, coconuts and potatoes, which could embed RFID (radio-frequency) technology to track data on products.

The findings draw on similar work the team did developing a material called laser-induced graphene (LIG), using a laser to heat the surface of a material to create a flaky, foamy form of graphene (a single layer of carbon atoms arranged in an hexagonal lattice).

'Edible electronics'

"This is not ink. This is taking the material itself and converting it into graphene," said Prof. James Tour, chemistry department, Rice University, Houston, Texas.

"Perhaps all food will have a tiny RFID tag that gives you information about where it's been, how long it's been stored, its country and city of origin and the path it took to get to your table."

The formerly invented LIG technique could become the new class of edible electronics.

The researchers discovered it wasn’t turning up the laser's power that made better graphene on a coconut or other organic materials but by adjusting the process, it allowed them to make a micro supercapacitor in the shape of a Rice "R" on their twice-lased coconut skin.

Tour claims because the graphene etchings are conductive the LIG tags could be used as sensors that detect E. coli or other microorganisms on food.

“They can potentially allow RFID tags and sensors to be embedded on foods directly, telling you the history of the item or warning you of potential micro-organic contaminants,” he said.

'Wonder' material

"Perhaps all food will have a tiny RFID tag giving information about where it's been, how long it's been stored, its place of origin and the path it took to get to the table.

"All that could be placed not on a separate tag on the food, but on the food itself."

Graphene is allegedly already known as a ‘wonder ‘ material because it is extremely thin and strong, a great conductor of heat and electricity and antibacterial.

LIG is a spongy version of graphene, the single-atom layer of carbon atoms. Tour and his team at Rice Univeristy developed it three years ago by burning partway through an inexpensive polyimide sheet with a laser, which turned the surface into a lattice of interconnected graphene sheets.

LIG also protects surfaces from biofouling, the buildup of microorganisms, plants or other biological material on wet surfaces.