Simulations of the frictional response of laser tweezed colloidal monolayers

Category: Scientific Highlights

Work of Jaffar Hasnain, Swetlana Jungblut and Christoph Dellago featured on the cover of Soft Matter

 

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 In an attempt to improve our understanding of the dynamics of friction, we simulated a monolayer of repulsive particles that were exposed to a hexagonal substrate potential and an external constant force along along one of its symmetry axis. For weak repulsion strengths the diffusion of individual defects is responsible for motion of the monolayer. As the interaction strength is increased, sliding is induced by distinct density compression and decompression zones. For very strong interactions, a type of stick-slip mechanism emerges, in which the sliding of the monolayer is mediated by the propagation of collective distortion waves.

In addition to these qualitative changes, analytical expressions were found that characterize the maximum, minimum and intermediate frictional responses. Our predictions can be tested experimentally with two-dimensional arrangements of colloidal particles exposed to periodic light fields and since we considered the simplest possible conditions, there still remain many avenues exploration.

 

Hasnain, Jaffar and Jungblut, Swetlana and Dellago, Christoph 2013
Dynamic phases of colloidal monolayers sliding on commensurate substrates, Soft Matter 9 5867-5873
[Abstract] [BibTeX] [doi] [Soft Matter] [Open Access]

First published online 29 Apr 2013

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