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Microbial fuel cells directly powering a microcomputer (2019)
Journal Article
Walter, X. A., Walter, A., Greenman, J., & Ieropoulos, I. (2020). Microbial fuel cells directly powering a microcomputer. Journal of Power Sources, 446, https://doi.org/10.1016/j.jpowsour.2019.227328

© 2019 The Authors Many studies have demonstrated that microbial fuel cells (MFC) can be energy-positive systems and power various low power applications. However, to be employed as a low-level power source, MFC systems rely on energy management circ... Read More about Microbial fuel cells directly powering a microcomputer.

Self-stratified and self-powered micro-supercapacitor integrated into a microbial fuel cell operating in human urine (2019)
Journal Article
Santoro, C., Walter, X. A., Soavi, F., Greenman, J., & Ieropoulos, I. (2019). Self-stratified and self-powered micro-supercapacitor integrated into a microbial fuel cell operating in human urine. Electrochimica Acta, 307, 241-252. https://doi.org/10.1016/j.electacta.2019.03.194

© 2019 The Authors A self-stratified microbial fuel cell fed with human urine with a total internal volume of 0.55 ml was investigated as an internal supercapacitor, for the first time. The internal self-stratification allowed the development of two... Read More about Self-stratified and self-powered micro-supercapacitor integrated into a microbial fuel cell operating in human urine.

Scalability of self-stratifying microbial fuel cell: Towards height miniaturisation (2019)
Journal Article
Walter, X. A., Santoro, C., Greenman, J., & Ieropoulos, I. A. (2019). Scalability of self-stratifying microbial fuel cell: Towards height miniaturisation. Bioelectrochemistry, 127, 68-75. https://doi.org/10.1016/j.bioelechem.2019.01.004

© 2019 The Authors The scalability of bioelectrochemical systems is a key parameter for their practical implementation in the real-world. Up until now, only urine-fed self-stratifying microbial fuel cells (SSM-MFCs) have been shown to be scalable in... Read More about Scalability of self-stratifying microbial fuel cell: Towards height miniaturisation.

Binder materials for the cathodes applied to self-stratifying membraneless microbial fuel cell (2018)
Journal Article
Walter, X. A., Greenman, J., & Ieropoulos, I. (2018). Binder materials for the cathodes applied to self-stratifying membraneless microbial fuel cell. Bioelectrochemistry, 123, 119-124. https://doi.org/10.1016/j.bioelechem.2018.04.011

© 2018 The Authors The recently developed self-stratifying membraneless microbial fuel cell (SSM-MFC) has been shown as a promising concept for urine treatment. The first prototypes employed cathodes made of activated carbon (AC) and polytetrafluoroe... Read More about Binder materials for the cathodes applied to self-stratifying membraneless microbial fuel cell.

Self-stratifying microbial fuel cell: The importance of the cathode electrode immersion height (2018)
Journal Article
Walter, X. A., Santoro, C., Greenman, J., & Ieropoulos, I. (2019). Self-stratifying microbial fuel cell: The importance of the cathode electrode immersion height. International Journal of Hydrogen Energy, 44(9), 4524-4532. https://doi.org/10.1016/j.ijhydene.2018.07.033

© 2018 The Author(s) Power generation of bioelectrochemical systems (BESs) is a very important electrochemical parameter to consider particularly when the output has to be harvested for practical applications. This work studies the effect of cathode... Read More about Self-stratifying microbial fuel cell: The importance of the cathode electrode immersion height.

Development of small scale ceramic Microbial Fuel Cells for clean energy extraction from urine (2018)
Presentation / Conference
Gajda, I., Walter, X. A., Obata, T., Greenman, J., & Ieropoulos, I. (2018, June). Development of small scale ceramic Microbial Fuel Cells for clean energy extraction from urine. Presented at 14th International Ceramics Congress 2018

During the last 20 years great interest in Microbial Fuel Cells (MFCs) has intensified due to the extraction of clean electricity from waste streams such as urine. The technology is based on ceramic built MFCs in which the terracotta chassis is also... Read More about Development of small scale ceramic Microbial Fuel Cells for clean energy extraction from urine.

PEE POWER® urinal II - Urinal scale-up with microbial fuel cell scale-down for improved lighting (2018)
Journal Article
Walter, X. A., Merino-Jiménez, I., Greenman, J., & Ieropoulos, I. (2018). PEE POWER® urinal II - Urinal scale-up with microbial fuel cell scale-down for improved lighting. Journal of Power Sources, 392, 150-158. https://doi.org/10.1016/j.jpowsour.2018.02.047

© 2018 The Authors A novel design of microbial fuel cells (MFC) fuelled with undiluted urine was demonstrated to be an efficient power source for decentralised areas, but had only been tested under controlled laboratory conditions. Hence, a field-tri... Read More about PEE POWER® urinal II - Urinal scale-up with microbial fuel cell scale-down for improved lighting.

Photoferrotrophy: Remains of an ancient photosynthesis in modern environments (2017)
Journal Article
Walter, X. A., Camacho, A., Walter, X. A., Picazo, A., & Zopfi, J. (2017). Photoferrotrophy: Remains of an ancient photosynthesis in modern environments. Frontiers in Microbiology, 8(MAR), 323. https://doi.org/10.3389/fmicb.2017.00323

© 2017 Camacho, Walter, Picazo and Zopfi. Photoferrotrophy, the process by which inorganic carbon is fixed into organic matter using light as an energy source and reduced iron [Fe(II)] as an electron donor, has been proposed as one of the oldest phot... Read More about Photoferrotrophy: Remains of an ancient photosynthesis in modern environments.

Urine transduction to usable energy: A modular MFC approach for smartphone and remote system charging (2016)
Journal Article
Walter, X. A., Stinchcombe, A., Greenman, J., & Ieropoulos, I. (2017). Urine transduction to usable energy: A modular MFC approach for smartphone and remote system charging. Applied Energy, 192, 575-581. https://doi.org/10.1016/j.apenergy.2016.06.006

© 2016 The Authors This study reports for the first time the full charging of a state-of-the-art mobile smartphone, using Microbial Fuel Cells fed with urine. This was possible by employing a new design of MFC that allowed scaling-up without power de... Read More about Urine transduction to usable energy: A modular MFC approach for smartphone and remote system charging.

Scaling-up of a novel, simplified MFC stack based on a self-stratifying urine column (2016)
Journal Article
Walter, X. A., Gajda, I., Forbes, S., Winfield, J., Greenman, J., & Ieropoulos, I. (2016). Scaling-up of a novel, simplified MFC stack based on a self-stratifying urine column. Biotechnology for Biofuels, 9(1), https://doi.org/10.1186/s13068-016-0504-3

© 2016 Walter et al. Background: The microbial fuel cell (MFC) is a technology in which microorganisms employ an electrode (anode) as a solid electron acceptor for anaerobic respiration. This results in direct transformation of chemical energy into e... Read More about Scaling-up of a novel, simplified MFC stack based on a self-stratifying urine column.

On hybrid circuits exploiting thermistive properties of slime mould (2016)
Journal Article
Ieropoulos, I. A., Walter, X. A., Horsfield, I., Mayne, R., Ieropoulos, I., & Adamatzky, A. (2016). On hybrid circuits exploiting thermistive properties of slime mould. Scientific Reports, 6(23924), https://doi.org/10.1038/srep23924

Slime mould Physarum polycephalum is a single cell visible by the unaided eye. Let the slime mould span two electrodes with a single protoplasmic tube: if the tube is heated to approximately ≈40 °C, the electrical resistance of the protoplasmic tube... Read More about On hybrid circuits exploiting thermistive properties of slime mould.

From single MFC to cascade configuration: The relationship between size, hydraulic retention time and power density (2016)
Journal Article
Ieropoulos, I. A., Walter, X. A., Forbes, S., Greenman, J., & Ieropoulos, I. (2016). From single MFC to cascade configuration: The relationship between size, hydraulic retention time and power density. Sustainable Energy Technologies and Assessments, 14, 74-79. https://doi.org/10.1016/j.seta.2016.01.006

© 2016 The Authors. Achieving useful electrical power production with the MFC technology requires a plurality of units. Therefore, the main objective of much of the MFC research is to increase the power density of each unit. Collectives of MFCs will... Read More about From single MFC to cascade configuration: The relationship between size, hydraulic retention time and power density.

Stability and reliability of anodic biofilms under different feedstock conditions: Towards microbial fuel cell sensors (2015)
Journal Article
Walter, X. A., You, J., Walter, X. A., Greenman, J., Melhuish, C., & Ieropoulos, I. (2015). Stability and reliability of anodic biofilms under different feedstock conditions: Towards microbial fuel cell sensors. Sensing and Bio-Sensing Research, 6, 43-50. https://doi.org/10.1016/j.sbsr.2015.11.007

© 2015 The Authors. Stability and reliability of microbial fuel cell anodic biofilms, consisting of mixed cultures, were investigated in a continuously fed system. Two groups of anodic biofilm matured with different substrates, acetate and casein for... Read More about Stability and reliability of anodic biofilms under different feedstock conditions: Towards microbial fuel cell sensors.

Microbial fuel cells continuously fuelled by untreated fresh algal biomass (2015)
Journal Article
Ieropoulos, I. A., Greenman, J., Walter, X. A., Taylor, B., Walter, X. A., Greenman, J., …Ieropoulos, I. (2015). Microbial fuel cells continuously fuelled by untreated fresh algal biomass. Algal Research, 11, 103-107. https://doi.org/10.1016/j.algal.2015.06.003

© 2015. Microbial fuel cells (MFCs) are energy transducers that convert organic matter directly into electricity, via the anaerobic respiration of electro-active microorganisms. An avenue of research in this field is to employ algae as the organic c... Read More about Microbial fuel cells continuously fuelled by untreated fresh algal biomass.

Fade to Green: A Biodegradable Stack of Microbial Fuel Cells (2015)
Journal Article
Walter, X. A., Chambers, L. D., Winfield, J., Chambers, L., Rossiter, J., Stinchcombe, A., …Ieropoulos, I. (2015). Fade to Green: A Biodegradable Stack of Microbial Fuel Cells. ChemSusChem, 8(16), 2705-2712. https://doi.org/10.1002/cssc.201500431

© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. The focus of this study is the development of biodegradable microbial fuel cells (MFCs) able to produce useful power. Reactors with an 8mL chamber volume were designed using all biodegradable produ... Read More about Fade to Green: A Biodegradable Stack of Microbial Fuel Cells.

Intermittent load implementation in microbial fuel cells improves power performance (2014)
Journal Article
Ieropoulos, I. A., Greenman, J., Walter, X. A., & Ieropoulos, I. (2014). Intermittent load implementation in microbial fuel cells improves power performance. Bioresource Technology, 172, 365-372. https://doi.org/10.1016/j.biortech.2014.09.034

© 2014 Elsevier Ltd. This study reports on the response of small-scale MFCs to intermittent loading, in terms of power output over time. The aim was to understand the evolution with time of power output under different duty cycles, in conditions clos... Read More about Intermittent load implementation in microbial fuel cells improves power performance.

Phototrophic Fe(II)-oxidation in the chemocline of a ferruginous meromictic lake (2014)
Journal Article
Miracle, M. R., Walter, X. A., Walter, X. A., Picazo, A., Miracle, M., Vicente, E., …Zopfi, J. (2014). Phototrophic Fe(II)-oxidation in the chemocline of a ferruginous meromictic lake. Frontiers in Microbiology, 5(DEC), https://doi.org/10.3389/fmicb.2014.00713

© 2014 Walter, Picazo, Miracle, Vicente, Camacho, Aragno and Zopfi. Precambrian Banded Iron Formation (BIF) deposition was conventionally attributed to the precipitation of iron-oxides resulting from the abiotic reaction of ferrous iron (Fe(II)) with... Read More about Phototrophic Fe(II)-oxidation in the chemocline of a ferruginous meromictic lake.

Oxygenic phototrophic biofilms for improved cathode performance in microbial fuel cells (2013)
Journal Article
Ieropoulos, I. A., Walter, X. A., Walter, X. A., Greenman, J., & Ieropoulos, I. (2013). Oxygenic phototrophic biofilms for improved cathode performance in microbial fuel cells. Algal Research, 2(3), 183-187. https://doi.org/10.1016/j.algal.2013.02.002

The rate of oxygen reduction reaction in the cathodic chambers of microbial fuel cells (MFCs) is a typical limiting aspect of its performance. Recently, research on biocathodes has gained more interest as it allows circumventing the utilisation of ex... Read More about Oxygenic phototrophic biofilms for improved cathode performance in microbial fuel cells.

The practical implementation of microbial fuel cell technology
Book Chapter
Ieropoulos, I., Winfield, J., Gajda, I., Walter, X. A., Papacharalampos, G., Merino Jimenez, I., …Greenman, J. (2016). The practical implementation of microbial fuel cell technology. In K. Scott (Ed.), Microbial Electrochemical and Fuel Cells, 357-380. Woodhead (Elsevier)

This chapter illustrates how microbially produced electricity can be harnessed directly to power applications and/or be used as a novel method of sensing. For applications requiring higher power, the continuous power produced will not be sufficient a... Read More about The practical implementation of microbial fuel cell technology.