Developing 3D-Printable Cathode Electrode for Monolithically Printed Microbial Fuel Cells (MFCs)

Abstract

Microbial Fuel Cells (MFCs) employ microbial electroactive species to convert chemical energy stored in organic matter, into electricity. The properties of MFCs have made the technology attractive for bioenergy production. However, a challenge to the mass production of MFCs is the time-consuming assembly process, which could perhaps be overcome using additive manufacturing (AM) processes. AM or 3D-printing has played an increasingly important role in advancing MFC technology, by substituting essential structural components with 3D-printed parts. This was precisely the line of work in the EVOBLISS project, which investigated materials that can be extruded from the EVOBOT platform for a monolithically printed MFC. The development of such inexpensive, eco-friendly, printable electrode material is described below. The electrode in examination (PTFE_FREE_AC), is a cathode made of alginate and activated carbon, and was tested against an off-the-shelf sintered carbon (AC_BLOCK) and a widely used activated carbon electrode (PTFE_AC). The results showed that the MFCs using PTFE_FREE_AC cathodes performed better compared to the PTFE_AC or AC_BLOCK, producing maximum power levels of 286 μW, 98 μW and 85 μW, respectively. In conclusion, this experiment demonstrated the development of an air-dried, extrudable (3D-printed) electrode material successfully incorporated in an MFC system and acting as a cathode electrode.

Carbonaceous Anodes and Compatible Exoelectrogens in High-Performance Microbial Fuel Cells: A Review

“…Therefore, exoelectrogens can be directly inoculated into the anode, resulting in a high bioactivity and electron transfer capacity. 154 In the protocol of direct 3D printing of MFC anodes with living EMCs, the culture solution of Shewanella oneidensis MR-1 was first mixed with sodium alginate and cellulose, and then the mixture was put into a 5 mL sterile syringe and loaded as the 3D printer ink. The resulting anode with living EMCs showed a dramatic decrease in internal alternating-current impedance, which was caused by the perfect fusion of MR-1 on the anode.…”

3D Composite PDMS/MWCNTs Aerogel as High-Performing Anodes in Microbial Fuel Cells

“…Several works in the literature investigated the fabrication of customizable 3D electrodes, characterized by a defined geometric structure and known channel sizes, confirming the potential for fabricating electrodes via 3D printing technology. This technology, however, is not sufficient to completely overcome the main limits of 3D electrodes, such as the low specific area available for bacteria adhesion, maintaining a low power output density [ 22 , 23 , 24 , 25 ]. Furthermore, in recent years, composite anode electrodes have attracted great interest [ 17 ], since these electrodes are characterized by two interconnected elements/portions: a polymeric layer suitable for creating the correct biocompatibility for bacterial proliferation and a conductive filler capable of enhancing the electron transfer from electroactive bacteria to the anodic surface.…”

Customizable design strategies for high-performance bioanodes in bioelectrochemical systems

“…Three dimensional printing technology, which enables the fabrication of customizable 3D electrodes with expected geometric structures and channel sizes, can be used to explore a desired 3D electrode ( Theodosiou et al., 2018 , 2020 ). Recently, Bian et al.…”