Small scale/large scale MFC stacks for improved power generation and implementation in robotic applications

Papacharalampos, Georgios

Abstract

Microbial Fuel Cells (MFCs) are biological electrical generators or batteries that have shown to be able to energise electronic devices solely from the breakdown of organic matter found in wastewater. The generated power from a single unit is currently insufficient to run standard electronics hence alternative strategies are needed for stepping-up their performance to functional levels. This line of work deals with MFC miniaturisation; their proliferation into large stacks; power improvement by using new electrode components and finally a novel method of energy harvesting that will enhance the operation of a self-sustainable robotic platform. A new-design small-MFC design was developed using 3D printing technology that outperformed a pre-existing MFC of the same volume (6.25 mL) highlighting the importance of reactor configuration and material selection. Furthermore, improvements were made by the use of a cathode electrode that facilitates a higher rate of oxygen reduction reaction (ORR) due to the high surface area carbon nanoparticles coated on the outer layer. Consequently, a 24-MFC stack was built to simulate a small-scale wastewater treatment system. The MFC units were connected in various arrangements, both fluidically as a series of cascades and electrically in-parallel or in-series, for identifying the best possible configuration for organic content reduction and power output. Results suggest that in-parallel connections allow for higher waste removal and the addition of extra units in a cascade is a possible way to ensure that the organic content of the feedstock is always reduced to below the set or permitted levels for environmental discharge. Finally, a new method of fault-proof energy harvesting in stacks was devised and developed to produce a unique energy autonomous energy harvester without any voltage boosting and efficiencies above 90%. This thesis concludes with the transferability of the above findings to a robotic test platform which demonstrates energy autonomous behaviour and highlights the synergy between the bacterial engine and the mechatronics.

• Thesis Type: Thesis
• Deposit Date: Mar 31, 2016
• Publicly Available Date: Mar 31, 2016
• Keywords: microbial fuel cells, stacks, energy harvesting, sustainable technology
• Public URL: https://uwe-repository.worktribe.com/output/906968
• Contract Date: Mar 31, 2016
• Award Date: Oct 28, 2016