Electrodeposited polypyrrole films doped with hexasulfonated calix[6]arenes are mainly cation exchangers during electrochemically induced doping/undoping processes in a 0,1 M KNO 3 solution. This is shown here from ion concentrations variations and time constants extracted from ac -electrogravimetry experiments. EIS measurements show that diffusion of ions in the solution is not the rate limiting step in these processes. In parallel, electrochemical AFM investigations revealed correlated swelling/shrinking processes. Actually, ion exchanges imply predictable and fast electromechanical processes that are followed by much slower thickness variations in the opposite direction resulting possibly from conformational relaxation phenomena involving the polymeric chains.