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

Abstract

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 cm2, the µPSC achieved its peak power output of 200.6 µW when exposed to an illumination of 2 µmolm−2s−1 (equivalent to 147 lux). Of the three light intensities studied, 2 µmolm−2s−1, 8 µmolm−2s−1 (595 lux), and 20 µmolm−2s−1 (1500 lux), the µPSC exhibited its optimal performance at a light intensity of 2 µmolm−2s−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−2s−1 illumination.

Keywords

• Bio-photovoltaics
• bio-solar cell
• photosynthetic cell
• clean energy
• microfabrication
• photo-bio-electrochemical cell