Design of a shared-stage charge pump circuit for multi-anode microbial fuel cells

Microbial fuel cells (MFCs) are promising renewable energy sources for long-term underwater systems. The critical limitations of MFCs include low output voltage and bioturbation interference. A multianode MFC was proposed in our previous work to tolerate bioturbation problems. Due to the unique structure of the multi-anode MFC, an anode decoupling function is needed for power management. Conventional designs based on separate charge pumps will have large overhead and performance degradation when anodes are impaired. In this paper, we address the above problems by developing a shared-stage charge pump circuit for voltage boosting and anode decoupling. The shared-stage design employs independent pumping units for each anode at the first stage and shared pumping units at the following stages. A new scheme is developed to prevent reverse currents at the impaired anodes. The proposed design significantly reduces the energy losses and improves the power efficiency of MFCs.