A New Approach to Measure Internal Resistance of Microbial Fuel Cells

A new approach of measuring the internal resistance of microbial fuel cells have been investigated. Our approach measures internal resistance applying a voltage scan that is dictated by the energy generating ability of the microorganisms. The voltage scan is employed by the charging a capacitor. It reflects true characteristic value of the internal resistance because time scale of the measurement is consistent with the time scale of microbial growth. The method is tested through experimental determination of the internal resistance of a microbial fuel cell inoculated with Shewanella oneidensis, MR-1. The results are analyzed using an equivalent circuit model and compared with internal resistance measured using current-step method. The results demonstrate that capacitor charging method can be an alternative electrochemical technique to measure internal resistance that considers time scale of microbial growth.