Mechanical forces can be used to trigger chemical reactions through activating bonds and to direct the course of such reactions in organic materials, particularly in polymers [Nature, 446, 381 (2007); Nature, 446, 423 (2007)]. In inorganic materials, the small molecules present significant challenges in directing the reaction kinetics. Using an in situ electrochemical-mechanical technique, we have generated oxides of tantalum with the assistance of mechanical forces in the tangential direction. Using this approach, we were able to control the amount of mechanical and electrical energy in a designed chemical environment. Meta-stable oxides, TaO and Ta2O, have been formed with mechanical forces. c 2007 The Electrochemical Society.