In this project we addressed the two following issues : what transfer intensification strategies can be set up to optimize the chemical and energetic yields in microbial fuel cells ? What are the most relevant methods to characterize and control the bio-electrochemical phenomenon that are taking place ? We first report two strategies regarding the reactor engineering that are (i) the use of reticulated vitreous carbon as high-surface area porous electrodes and (ii) the use of constructal approach as a multi-scale optimization for fluid distribution. Advantages and limits are discussed. In a second part, we address some basic research which aims at identifying and characterizing the electrochemical phenomenon occurring in our reactor and quantifying the effect of various physicochemical (temperature, conductivity, buffer and substrate concentration) and material factors (oxydized RVC, platinized air-cathode, membrane thickness, cathode surface area). This multifactorial analysis was performed using Tagushi experimental plans and electrochemical impedance spectroscopy (IES). IES was successfully used to simulate our electrodes and cell phenomenon based on electrical analogies using resistive and capacitive elements.