Graphene is the wonder material that just
keeps on giving.
Actually, it's the reported wonder material
that keeps on promising it can give but so
far has been a bit flakey, promising advances
in electronics, fabrics, construction materials,
information systems and countless other fields,
but singularly failling to deliver commercially
viable products.
Graphene is great.
In fact it's better than the inherently imperfect
technology currently used to produce it, which
makes it, for now, a bit useless.
And now there's yet another incredibly useful
thing that graphene has found to be capable
of - it can generate electricity from saltwater.
A team of researchers from China found that,
by placing a droplet of saltwater on a graphene
film and then dragging it along, they could
generate a small voltage difference.
More drops moved faster generated a linear
increase in the amount of voltage producecd.
So what's caused it?
Well the team foudn that when the drop was
still, the charge distribution between the
graphene on either side of the drop was equal.
When it moved, it created a charge difference
- the electrons desorbing from one side of
the strip and absorbed into the graphene at
the other.
This means that with a regular flow of salt
water over the strip, a constant, potentially
useful charge can be created.
The amounts are pretty small - in the test,
one droplet created about 30 millivolts.
But it can be scaled up, with some serious
advantages.
Most hydroelectric and tidal power systems
are monumental engineering feats, requiring
millions of tonnes of concrete and large scale
destruction of ecosystems and shorelines.
Nano materials such as graphene require much
less engineering and infrastructure, and therefore
damage.
And because graphene can be created from more
or less anything carbon based, from wood to
dog poo, it would be relatively cost effective
too.
But like all other graphene related advances,
manufacturing is the major stumbling block.
We simply can't make enough graphene in large,
continuous quantities to be industrially viable.
Yet.
