Optical Interactions in Bio-Electricity Generation from Photosynthesis in Microfluidic Micro-Photosynthetic Power Cells

Within the realm of renewable energy sources, biological-based power systems have emerged as pivotal players particularly suited for low- and ultra-low-power applications. Unlike microbial fuel cells (MFCs), which invariably rely on external carbon feedstock, micro-photosynthetic cells (µPSCs) exhibit a unique feature by operating independently of organic fuel. They harness the principles of photosynthesis and respiration to generate electricity in both illuminated and dark settings through water-splitting reactions. Here, we present a viable, easy, and cost-effective method to fabricate µPSCs. We meticulously examined the performance of a fabricated µPSC under varying illuminations and even in the absence of light. With an electrode surface area spanning 4.84 cm 2 , the µPSC achieved its peak power output of 200.6 µW when exposed to an illumination of 2 µmolm −2 s −1 (equivalent to 147 lux). Of the three light intensities studied, 2 µmolm −2 s −1 , 8 µmolm −2 s −1 (595 lux), and 20 µmolm −2 s −1 (1500 lux), the µPSC exhibited its optimal performance at a light intensity of 2 µmolm −2 s −1 , establishing this as the ideal operational illumination. Furthermore, intermittent toggling of the illumination had no discernible impact on the µPSC’s performance. However, subjecting it to a dark environment for 30 min resulted in a reduction in the maximum power to 81 µW, marking a significant 119% decrease when compared to the peak power output achieved under 2 µmolm −2 s −1 illumination.