​Sometimes it is important to show what directions we should not take or we need to overcome. “Power Degradation In Series Connected Multiple Single Feeding 40 µL Microbial Fuel Cells” by Jhonathan Prieto Rojas, Wejdan Alqarni and Muhammad Mustafa Hussain is one of those few. We have developed and studied sustainable, single feeding, micro-sized, air-cathode and membrane-less microbial fuel cells with a volume of 40 µL each, which we have used for rapid evaluation of power generation and viability of a series array of three cells seeking higher voltage levels. The achieved power density was modest (45 mW/m³), which was limited due to non-uniformities in assembly and the single-channel feeding system. The paper will be published in Energy Technology (Wiley VCH) which we hope to be a cover page – keep striking team!