The proposed research focuses on the development of novel microelectrodes for stimulating neural activity. Electrodes for in situ applications in neural electrical stimulation should be small in size, corrosion resistant and long lasting under pulsing conditions in biological fluids. The goal of this study is to develop and fabricate a prototype neural stimulating biocompatible electrode for prosthetic application that will be smaller in size than existing electrodes yet long lasting under pulsing conditions in biological fluids. Phase I will deal with single electrodes and phase II with silicon based arrays of electrodes. The electrochemical response and the surface properties will be monitored in solutions simulating extracellular fluids and in actual body fluids under stimulating conditions. The effect of various pulsing techniques: current symmetrical charge balanced, current asymmetrical charge balanced, and current asymmetrical non-charge balanced on the electrode performance will be studied. In situ STM will be used to both fabricate the micro scale electrodes, as well as to continuously monitor their surface properties.