Nanopattern influence on friction, wear, and adhesion
Molecular Physics seminar
Monday 12 October 2015
to 11:00 at
Patricia Pedraz (IMDEA Nanociencia, Madrid)
Ripples are waves or undulations that are formed on surfaces. They can appear naturally on the sand and rocks due to water or wind erosion or be produced artificially, even on the nanoscale.
On the first part of the talk, I will focus on the study of the influence of loading force, scan velocity and mechanic vibrations on the formation of ripples when a compliant polymer surface is scraped by an AFM tip. The load and velocity dependence of the ripple patterns observed experimentally can be reproduced within an extended version of Prandtl-Tomlinson model (1). In addition, the ripple formation is efficiently masked if out-of-plane vibrations are applied while scanning and this effect is enhanced at the contact resonance of the system. In these conditions, friction and wear are significantly reduced (2).
The second part of the seminar will deal with the applications of ripples made on glass in nanobiomedicine. These glass nanopatterned substrates are produced by ion beam sputtering and can be used as a scaffold for modifying cell adhesion and orientation (3).
1. Gnecco, E., Pedraz, P., Pawel, N., Dinelli, F., Napolitano, S. and Pingue, P. Surface rippling induced by periodic instabilities on a polymer surface. s.l. : New Journal of Physics, 2015. Vol. 17, 3. DOI: 10.1088/1367-2630/17/3/032001.
2. Pedraz, P., Wannemacher, R. and Gnecco, E. Controlled Suppression of Wear on the Nanoscale by Ultrasonic Vibrations. s.l. : ACS Nano, 2015. DOI: 10.1021/acsnano.5b02466.
3. Pedraz, P., Casado, S., Rodríguez, V., Giordano, M.C., Buatier de Mongeout, F., Ayuso-Sacido, A. and Gnecco, E. Adhesion modification of neural stem cells induced by ripple nanopatterns, submitted.