Per and Poly‐Fluoroalkyl‐Free PVA Membrane Separator for Sustainable Energy Recovery From Municipal Wastewater Using Biomimetic Miniature Microbial Fuel Cell

Microbial fuel cells (MFCs) have emerged as a viable alternative in the search for sustainable bioenergy and efficient wastewater treatment. This work introduces the creation of a biomimetic, miniaturized MFC that utilizes nature‐inspired flow channel design and eco‐friendly materials to enhance electrochemical performance and reduce overall costs. A micron‐scale, heart‐shaped flow channel was constructed to provide continuous micromixing of the effluent at both the anode and cathode, enhancing mass transfer, substrate utilization, and bacterial‐electrode interactions. A PFAS‐free, laboratory‐synthesized membrane was used as a charge separator, replacing the conventional Nafion 117 membrane, to eliminate costly and ecologically detrimental components. A custom‐designed Arduino‐UNO‐based smart data recording system was included for real‐time voltage monitoring, providing a cost‐effective substitute for commercial multimeters. The MFC attained a peak columbic efficiency of 85.5% and exhibited a concurrent chemical oxygen demand (COD) elimination efficiency of 68% ± 0.10% when processing municipal wastewater. A thorough techno‐economic study indicated that the overall cost of the system was 46.10 USD/ft 2 , making it around eight times more cost‐effective than conventional Nafion‐based MFCs. The decrease in costs, together with enhanced electrochemical and treatment efficacy, highlights the system's scalability and practical feasibility for decentralized wastewater treatment and energy production.