Invited Paper TR+NS+SS-WeA3
Atomic-scale Processes in Friction and Wear: From Diamond to Graphene

Wednesday, October 20, 2010, 2:40 pm, Room Tesuque

Nanoscale friction and wear are primary limitations for small-scale devices such as atomic force microscopy (AFM) probes and micro- or nano-electronic mechanical systems with contacting surfaces, and is also relevant to understanding friction and wear in larger-scale contacts. We first present studies that quantify the nanoscale volume loss in sliding wear using AFM and periodic ex-situ transmission electron microscopy (TEM) imaging. Novel carbon-based AFM tip materials, including ultrananocrystalline diamond and diamondlike carbon, exhibit superior wear resistance compared to conventional materials (silicon and silicon nitride)^1-3. We then present results from wear tests performed inside of the TEM using modified in-situ indentation techniques. This permits real-time visualization of the contact geometry and shape evolution of a single asperity with sliding over a countersurface. This allows us to measure wear with a higher degree of precision than previously possible. Insights comparing the wear resistance of carbon-based and Si-based materials, particularly in the context of atom-by-atom wear processes, will be discussed⁴. Finally, we will discuss how nanoscale friction in graphene and other atomically-thin sheets is governed by the high flexibility intrinsic to the atomic scale⁵.

1. Prevention of nanoscale wear in atomic force microscopy through the use of monolithic ultrananocrystalline diamond probes. J. Liu, D.S. Grierson, J. Notbohm, S. Li, S.D. O’Connor, K.T. Turner, R.W. Carpick, P. Jaroenapibal, A.V. Sumant, J.A. Carlisle, N. Neelakantan & N. Moldovan, Small, in press (2010).

2. Ultra-low nanoscale wear through atom-by-atom attrition in silicon-containing diamond-like-carbon. H. Bhaskaran, B. Gotsmann, A. Sebastian, U. Drechsler, M. Lantz, M. Despont, P. Jaroenapibal, R.W. Carpick, Y. Chen & K. Sridharan, Nature Nanotechnology 5, 181-185 (2010).

3. Wear resistant diamond nanoprobe tips with integrated silicon heater for tip-based nanomanufacturing. P.C. Fletcher, J.R. Felts, Z. Dai, T.D. Jacobs, H. Zeng, W. Lee, P.E. Sheehan, J.A. Carlisle, R.W. Carpick & W.P. King, ACS Nano, accepted (2010).

4. On the application of transition state theory to atomic-scale wear. T.D. Jacobs, B. Gotsmann, M.A. Lantz & R.W. Carpick, Tribol. Lett., accepted (2010).

5. Frictional characteristics of atomically-thin sheets. C. Lee, Q. Li, W. Kalb, X.-Z. Liu, H. Berger, R.W. Carpick & J. Hone, Science 328, 76-80 (2010).