Click to return to the VINSE homepage

March 14, 2007


Dr. Tom Dickinson
Regents Professor
Paul A. Anderson Professor of Physics, Professor of Materials Science
Washington State University
"Synergistic mechanisms for material removal from surfaces: combined mechanical and chemical stimuli at the nanometer size scale"

Abstract. Bond breaking at surfaces due to stimuli such as exposure of materials to electrons, ions, photons, mechanical stress, or chemical agents is well established.  By applying multiple stimuli we show that synergistic effects often occur, wherein the degradation and modification of materials and solid surfaces are enhanced.  We show the nanometer-scale consequences of simultaneous localized mechanical stress (due to sliding contact with an atomic force microscope--AFM tip) and exposure to aqueous solutions.  These studies illustrate the underlying mechanisms underlying chemical mechanical planarization (CMP).  We illustrate our studies on single crystal specimens, including Si and polycrystalline metal surfaces.  We are studying the details of nanoscale tribochemistry, emphasizing results concerned with tip-induced tribochemical material removal, recrystallization (at small normal forces), and unique patterning produced by scanning in super-saturated aqueous solutions.  If time permits, we also present results on the influence of an SFM tip in contact with polymers immersed in organic solvents, and show a new method for introducing very small amounts of highly localized patches of chemicals into a polymer surface. 

Vanderbilt University