Tetrahedral amorphous diamond-like carbon (ta-C) films are characterized by extreme strength, modulus, durability, inertness to chemical agents, and low friction. These special properties may enable the fabrication of durable and reliable MEMS and NEMS devices. This award will help to establish the connection between microfabrication, material nanostructure, and mechanical properties of freestanding thin (ta-C) films. The focus of this research is on the effects of fabrication parameters, post fabrication treatment, and sp3/sp2 carbon bonding ratio on the mechanical properties of freestanding ta-C films. The research will be conducted in close collaboration with Sandia National Laboratories who are developing a unique process for the fabrication of robust ta-C MEMS. Measurements will be conducted via electrostatically actuated microdevices as well as externally actuated test structures, currently under development at the PI's laboratory. The local deformations/strains will be predominately measured via Atomic Force Microscopy based methodologies. The investigation is expected to support our understanding of the sub-micron fatigue and fracture phenomena in ta-C films, provide quantitative evidence for the development of composition-based predictive models for material mechanical behavior, and contribute to the optimization of Sandia's current microfabrication process for robust at-C MEMS and NEMS devices. The multidimensional character of this research program will provide interdisciplinary education and training to graduate as well as undergraduate students who will conduct their degree theses in the fields of MEMS, nanomechanical materials characterization, and scanning probe microscopy, and attend the special interdisciplinary courses offered by the PI at the University of Virginia.
