Combination of electric fields and Joule self-heating is used to change the oxygen stoichiometry and promote oxygen vacancy drift in a freestanding (La,Sr)MnO3 thin film microbridge placed in controlled atmosphere. By controlling the local oxygen vacancies concentration, we can reversibly switch our (La,Sr)MnO3-based microbridges from metallic to insulating behavior on timescales lower than 1 s and with small applied voltages (@en