Diamond films grown on different substrates are of interest for various applications - particularly in this contract to develop microelectrodes for deep brain stimulation. Despite studying diamond thin films for over a decade, questions remain about the effects of growth conditions that correlate with their properties. The aim here is to understand the evolutions of the structure of diamond films with changes in their growth conditions by chemical vapor deposition and the substrates used. Structural changes associated with the distribution of different constituents (i.e., sp3 or sp2 hybridized carbon) throughout the diamond thin film and the extent of the formation of hydrocarbons and defects will be analyzed in detail using spectroscopic and microscopic confocal Raman. Dr. Manciu will be responsible for coordinating all the essential measurements proposed and for analyzing the data acquired during the duration of the contract. By employing such characterizations, the composition of the thin films can be determined semi-quantitatively. Using confocal Raman mapping, the visualization of the local distribution of the constituents and unwanted defects or residues is possible [1-5]. The candidate microelectrodes fabricated at the Mayo Clinic in Rochester, Minnesota, will be characterized in detail at The University of Texas at El Paso. The results of this research will serve as reference points for further in vitro and in vivo investigations of the microelectrodes using FSCV and MCSWV.