Facile polymer-based monolithic microbial fuel cells

Additive manufacturing technologies have shown promising results over conventional methods in fabricating all components of energy devices. A relentless drive to fabricate all critical components in a single step is the core driving force. In the current work, monolithic microbial fuel cells (MFCs) are evaluated using Porolay series filaments, replacing multilayer cellulose paper substrates-based MFCs for the first time. Leveraging the benefits of 3D printing, different filaments of the Porolay series are employed for varying the thickness and internal architectures of critical components such as membranes, electrodes and reservoirs, targeting the maximum throughput. Amongst four different filaments, the Gel lay performed the best in terms of power output. The optimised thicknesses are membrane 0.4 mm, reservoir 1 mm, and layer above reservoir 0.6 mm. Further, facile electrodes are developed, combining screen printing and drop casting using an electric paint, which covers the surface as well as the internal strands of the printed substrate, enhancing the electron-capturing sites. Based on the optimised critical components and filaments, the monolithic printed substrate is able to generate a stable OCV of 0.49 V for approximately 90 min and deliver a power of 12.3 μW/cm2 using E. Coli as the biocatalyst. This low-cost device can assist point-of-care testing as a freestanding power source.