Autonomous power supply of a temperature sensor using a network of microbial fuel cells coupled with a power...

Microbial fuel cells (MFCs) are emerging bioelectrochemical systems capable of converting organic matter directly into electricity through the activity of electroactive microorganisms. Their ability to operate in humid and low-maintenance environments makes them an attractive option for powering autonomous monitoring devices. This study presents the design and validation of a self-sustaining temperature sensor powered by a hybrid energy system combining a network of MFCs with a power management system (PMS). The MFCs were inoculated with mangrove sediments, providing a resilient microbial community adapted to saline and anoxic conditions. The network consisted of four MFCs arranged as two parallel-connected pairs linked in series to balance voltage and current output. The system achieved a maximum power density of 248 mW.m^-2 with an overall internal resistance of 315 Ω. The PMS stabilized, stored, and regulated the harvested energy, supplying a steady 3.6 V to the temperature sensor. Continuous operation was maintained for five days without performance loss, and the stored energy indicated potential for extended autonomy. Beyond its technical validation, this work highlights the relevance of MFC-based energy harvesting in isolated or insular regions, where energy independence and low-maintenance solutions are critical for long-term environmental monitoring. The results confirm that sediment-based MFC networks can serve as renewable, sustainable power sources for low-energy sensing devices deployed in remote ecosystems such as mangroves.