Many bacterial cells are able to connect their metabolism with an electrode. Since the publication of the pioneering articles of 2002, the variety of bacterial species that have proved to be capable of extracellular electron transfer (EET) has been constantly expanding, and it now seems to be a current and ubiquitous lifestyle for microbial cells. EETs are most often correlated with essential metabolic pathways, particularly the respiratory metabolism of bacteria. The electrochemical approach of EETs is thus revolutionizing the understanding of microbial processes in most ecosystems. Numerous elements of the biomedical literature show that similar EETs, i.e. involving metabolic pathways, exist with human cells. For example, stem cells are commonly grown on conductive materials whose electrochemical properties drive differentiation into the different phenotypes. The exchange of extracellular electrons, in the form of "bioelectricity", is known to play essential roles in tissue repair or organ morphogenesis. In addition, human cells are eukaryotic cells and EETs associated with metabolic pathways have already been evidenced with yeasts, which are also eukaryotic cells. Despite the accumulation of indirect evidence of the occurrence of EETs with human cells, electrochemical approaches have never been implemented in this context before. Using the experience gained on microbial EETs by the consortium, the TECH project aims to build the electrochemical devices that will bring to light metabolic EETs with human cells. Three types of cells will be implemented: i) MRC5 lung cells, which have already given promising preliminary results, ii) progenitor cells from human adipose tissue, whose differentiation into white or beige adipocytes is related to the status of the respiratory metabolism and, iii) different cancer cell lineages, as the cancerous state of the cells could be correlated with dysfunction of the respiratory metabolism. The objective is to create the electrochemical reactors and electrode surfaces and to design the operating and analytical procedures that will allow EETs to be characterized during the development and/or differentiation of cells. The project will build synergy between two research groups belonging to the same laboratory, one mastering the EETs of microbial cells and the other the culture of human cells. In addition, two experts in the cellular metabolism of stem cells and cancer cells are associated as consultants. An interdisciplinary group will thus be created to combine skills in bioelectrochemistry, electroanalysis, cell adhesion, culture and cellular metabolism, and to couple electrochemical analysis methods with biochemical, biological and imaging techniques by microscopy. The project is submitted to the “Défi des autres savoirs” because the objective is to bring experimental evidence of a new paradigm. The project is applying for a modest budget because the objective is not to push investigations towards fundamental biology. This is a seminal project that intends to prove the concept of EET with human cells in order to convince the biomedical communities and to build further projects with them, having larger budgets on specific applied objectives. Demonstrating the occurrence of EETs with human cells will pave the way to new stem cell culture techniques, new tools for investigating cellular metabolisms and the pathologies, such as obesity and cancer, which are associated with their dysfunction and, we hope, will bring to light new therapeutic pathways.