60 / 116
60 E L EC TR I C AL CONNEC T I ON
W I N T E R 20 1 6
THEREWEE GO
I
t may not be the most glamorous
idea but researchers are hoping
urine-powered microbial fuel cells
(MFCs) will be a useful energy source in
the future.
Back in 2002, University of the West
of England PhD student, Dr Ioannis
Ieropoulos was part of a project to
build an energetically autonomous
robot. Various technologies were
being considered and Ioannis started
experimenting with feeding MFCs
different chemical substances to see how
much electricity could be generated.
“Back then it was more out of scientific
curiosity than something that could be
practically implemented,” he says.
Ioannis soon discovered the chemical
properties of wastewater, dead flies,
prawn shells and rotten fruit had
potential to be a viable electricity
generator. Over the subsequent 14 years,
he and his team have been researching
the mechanisms involved to develop an
understanding of how to more efficiently
use the chemicals to generate electricity.
As a result of this work, the team also
discovered that urine is an excellent fuel
for microbial electricity generation, due
to its constituent chemicals sodium,
phosphorous, potassium and nitrate
(among many others).
“We started by figuring out how urine
could be chemically broken down. Once
we established it could be done by the
microbes for electricity production we
then asked what we could use it for.”
The team has developed MFC-
integrated wearable socks that use a
flow of urine to generate electricity
through an oxidation reduction process.
Every MFC system in the past had
used a main power source to generate
electricity but this wearable has a tubing
system that uses footsteps as a pump
to create the flow of urine, to pass over
the MFCs.
The team successfully powered a
wireless transmitter to send a signal to a
PC proving they had made the first ever
self sufficient MFC electricity generator.
“The wearable is at an early stage of
development but we are hoping to push
out the technology as a commercial
product in the future,” Ioannis says.
Through support and funding from
the Bill and Melinda Gates Foundation
and the Engineering & Physical Sciences
Research Council there is another
direction the research may lead that is
closer to commercialisation.
MFCs may have potential as a
technology that could be integrated with
toilet facilities to generate electricity and
at the same time clean the waste so it
doesn’t spread disease.
The technology produces low levels
of power, which can be used for low
powered lighting or recharging electronic
devices but if appropriately scaled it could
potentially be used for whole households
or communities. The research team is
exploring these capabilities for MFCs.
With human waste as an energy
source, through MFC technology
wherever there are people there can be
sustainable energy.
“I would like to think there is a big role
for MFCs in future energy production.
It simply depends on how well we do
the engineering and how efficiently we
implement the technology because it
has numerous applications and can be
incorporated into many different aspects
of everyday life.”
AS THERE BECOMES MORE OF A
FOCUS TO REDUCE RELIANCE ON
FOSSIL FUELS AND SEARCH FOR
VIABLE RENEWABLE ENERGY
SOURCES, ONE ALTERNATIVE
COULD BE WITHIN US ALL.
JOE
YOUNG
REPORTS.
MFC-integrated wearable socks use a flow of urine to generate electricity.
WEIRD SCIENCE