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The extremely thin and strong substance
– the world’s only man-made 2D material
that’s a mere atom thick - is a good conductor
of heat and electricity, several times
stronger than steel, 100 times more conductive than
copper, antibacterial and can hunt down cancer…and
now a new strain can be printed onto food via laser.
A commercial laser can transform surface carbon in
foods like toast, coconut shells, potatoes and Girl
Scout cookies into graphene without using any special
vacuums or clean rooms – making the substance
able to be patterned into an impossibly thin edible
circuit, which includes fuel cells to store power, radio
hardware to transmit data and glowing elements…
all resembling a dark, inky tattoo like very burnt toast.
According to researchers, the graphene etchings will
allow RFID tags and sensors to be embedded on
foods directly, giving the history of the item and warning
of potential microorganism contaminants. Project
head Dr James Tour says the technique uses a laser
to heat the surface of a material to create a flaky,
foaming form of graphene. Researchers have now
managed to apply the technique to a whole range
of materials, and have found the best results come
when the laser is ‘defocused’ and makes several
passes over the material. “In some cases, multiple
lasing creates a two-step reaction,” Tour says. “First,
the laser photothermically converts the target surface
into amorphous carbon. Then on subsequent passes
of the laser, the selective absorption of infrared light
turns the amorphous carbon into LIG. We discovered
that the wavelength clearly matters.” As well as
cardboard, paper, cloth, cork and coal, the technique
can work on food such as bread, potatoes and
coconuts. Tour says the key seems to be an organic
polymer known as lignin, which is present in all those
materials and is also what allows dried wood to form
graphene. With its success in cloth, other applications
could include wearable sensors or even clothing
that warms up easier, thanks to graphene’s thermal
conductivity, he says. The research was published in
the journal ACS Nano.
The small bony and oily fish is expected
to bring beneficial income into the
country via the three-year project,
which has funding from the New Zealand Aid
Programme (administered by the Ministry of
Foreign Affairs and Trade). Wintec research
team manager Dr Debbie Care says offshore
fisheries in the Solomons are depleted, with
a lack of protein in the local diet causing
health issues. “It’s subsistence living for
many people in the Solomons…they grow it,
catch it or go without,” Care says. “Not many
people can imagine the level of subsistence,
but Solomon Islanders are rich in many ways.
They don’t have a lot, but they are incredibly
generous and very keen to develop their
resources.” Surrounded by sea, it would be
easy to assume island people have access to
a viable food and business resource, but Care
says large scale sea fishing means communities
now have to sail further for their catch,
requiring boats and equipment that they
do not have. Developing aquaculture is one
answer and the tilapia, an inland freshwater
fish introduced in the 1950s as a food source,
offers potential to develop aquaculture as
a sustainable and profitable option for the
people of the Solomon Islands. “One of our
challenges is online connectivity and communications,”
Care says. This means that despite
a high uptake of mobile technology there is
limited internet coverage, and this inspired
the Wintec team to develop an offline app
with the community to support education.
“The app is instructional and looks at all
aspects of fish farming including managing
fish ponds, cooking and preserving fish and
basic financial literacy. It’s an evolving project
- our next steps are to take the App back to
the Solomon Islands’ tilapia farmers to get
feedback. Meanwhile we are looking for more
farmers to test the app for ease of navigation
and to develop a level of intuitiveness to map
their thinking.” Looking ahead three years,
Care says Wintec aims to impact at least 500
community members through the initiatives
developed under the scheme. “There will be
value-added business opportunities, more
protein in the diet and cashflow in the family
home. The app will continue to be developed
to include recipes, financial information, as
well as better ways to farm tilapia through
education.”
EDIBLE LABELLING
Etching edible graphene onto food like bread and potatoes to act as an
RFID tag is one step closer to fruition, with an announcement by New Yorkbased
Rice University that a new laser is able to mark food.
TILAPIA FISHING
FARMING
HELPED BY KIWI
RESEARCHERS
Wintec researchers are working
with farmers in the Solomon
Islands’ Malaita province to
develop better ways of farming
tilapia fish in inland ponds.
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