Tribology is the science and technology of two interacting surfaces in relative motion, such as friction, wear, adhesion, and lubrication. The significance of tribology has been recognized recently because of economic reasons and has emerged as an independent area of science and technology. The continuing desire to miniaturize devices demands a complete understanding of tribological properties of surfaces of moving components on an atomic or molecular level and moves conventional tribology to an ultra-small scale, referred to as nano-tribology. A few examples of its application are magnetic storage devices such as computer hard disk drives (HDD), microelectromechanical systems (MEMS), and chemical mechanical planarization (CMP) processes in semiconductor fabrication.
An atomic force microscope (AFM) is an indispensable tool to explore atomic scale friction, wear, and lubrication of surfaces, because it models a tribological contact by using a probe tip as a model of a single microasperity. AFM also produces images (images of topography, friction force, magnetic force, chemical force, etc...) of a sample surface by scanning an unmodified or modified sharp tip mounted on a flexible cantilever with a spring constant typically between 0.1 and 100 N/m over the sample surface at fixed or variable loads.
A self-assembled monolayer (SAM) is a two-dimensional molecular array that is spontaneously organized by adsorption of amphiphilic organic molecules on a solid inorganic surface. The interfacial properties of SAMs such as friction and adhesion are decisive criteria for good lubricants which are significantly dependent upon their molecular structure, chain length, packing order, packing density, chemical composition, and molecular termination. Professor Lim's research is focused on the frictional properties of organic self-assembled monolayers formed on the surfaces of metal or metal oxides.
Montgomery, T.D.; Buchbinder, J.R.; Gawalt, E.S.; Iuliucci, R.J.; Koch, A.S.; Kotsikorou, K.; Lackey, P.; Lim, M.S.; Rohde, J.J.; Rupprecht, A.; Srnec, M.N.; Evanseck, J.D. “The Scientific Method as a Scaffold to Enhance Communication Skills in Chemistry”, Journal of Chemical Education, Vol 99 (6), 2022, 2338–2350.
Goswami, J. R. Nightingale, J. A. Duperre III, M. S. Lim, J. M. Dawson, A. Timperman, D. Korakakis and L. A. Hornak, “Surface Loading Sensitivity Characterization of a Resonant Planar Optical Waveguide Stack”, IEEE Photonics Technology Letters, Vol 24 (9), 2012, 778-780.
S. Lim, K. Smiley, E. S. Gawalt, “Thermally Driven Stability of Octadecylphosphonic Acid Thin Films Grown on SS316L”, Scanning, Vol 32 (5), 2010, 304-311. (An invited Paper from Scanning: the Journal of Scanning Microscopies)
S. Lim, K. Feng, X. Chen, N. Wu, A. Raman, J. Nightingale, E. S. Gawalt, D. Korakakis, L. A. Hornak, A. T. Timperman “Adsorption and Desorption of Stearic Acid Self-Assembled Monolayers on Aluminum Oxide", Langmuir vol. 23(5), 2007, 2444-2452.