Iwona Gajda
SELF SUSTAINABLE CATHODES FOR
MICROBIAL FUEL CELLS
Microbial Fuel Cells (MFCs)
Research Group

Energy “locked” in organic matter may be
liberated by the use of microorganisms
Michael C. Potter 1911 – First MFC
Generated power from cultures of Escherichia coli
MFC Technology is already 100 years old!
Major improvements in the technology in the last
10 years
Fermentation
Decomposing
Pharmaceuticals
Wastewater treatment
Microorganisms are only catalysts
Not a source of electrons
Microorganisms can drive electrons to the anode by
oxidising the organic matter
Gastrobot (Chew-chew) train invented by S. Wilkinson (University of South
Florida) 2001
Ecobot I (2001) performs phototaxis
Ecobot II (2003) performs phototaxis,
sensing, communication
The Ecobots
employ any other form of conventional power supply and
do not require any form of initial charging from an external source
Both developed by researchers at Bristol Robotics Laboratory:
Dr I.Ieropoulos, Prof J. Greenman, Prof C.Melhuish and I.Horsfield
Ecobot III (2008) -48 small-scale Microbial Fuel Cells,
world's first robot to exhibit true self-sustainability
Powering underwater
monitoring devices
Wastewater
treatment
Power supply to remote sensors
Powering small
everyday use
devices- mobile
phones
Powering
autonomous
robots
Though this technology is quite promising as a
source of renewable energy, it will be some
time before large-scale, highly efficient MFCs
enter the commercial scene.
S
L
U
D
G
E
ANODE
Before
Research based on:
CATHODE
- Anode improvement
- Cathode improvement
- Scalability and stacks
After
To develop:
Self sustainable
Cost efficient
Better performing
Improvement of:
Design
Electrode materials
Methodology
CATHODE
Platinum
.....expensive
Ferricyanide .....non sustainable and toxic
Photosynthetic
Organisms:
Algae
Cyanobacteria
Produce Oxygen
Use CO2 and light
Self sustainable
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



75% world’s oxygen is produced by marine
algae
Naturally occurring
Fast grown
Already used as biofuel source
Used also in wastewater treatment
Biocathode types
Abiotic cathode
Photoreactors
Biotic cathode
BIOCATHODES
ABIOTIC
CATHODE


Biotic cathodes outperform abiotic (water based)
cathodes
Photosynthethic organisms multiply creating
more biomass that might be used as a substrate!
Comparison between pure and mixed culture
algae and cyanobacteria
Various metals as current collectors
Different design, stacking
MFC Team:
Dr Ioannis Ieropoulos
Prof John Greenman
Prof Chris Melhuish
www.brl.ac.uk
Iwona.Gajda@uwe.ac.uk
University of the West of England
Frenchay Campus
North Entrance
Bristol