Seminários

Seminário de Mecânica Estatística

O seminário de Mecânica Estatística desta semana será apresentado na 6a feira, 26/04/2013, às 16:00h, na sala A5-01 do Instituto de Física. Ele será apresentado pelo Dr. Olivier Pierre-Louis, da Universidade de Lyon 1, França.

Título: Adhesion of membranes and filaments on nano-patterned substrates

Apresentador: Olivier Pierre-Louis (Universidade de Lyon 1, França)

Resumo:
Substrate patterning is shown to be a convenient method to control the adhesion
of membranes and filaments for objects of biological interest (such as lipid
membranes and actin filaments), and for carbon nanostructures (e.g. graphene
and nanotubes).  From a simple one-dimensional model, we find infinite
staircases of periodic partial unbinding transitions, and an unbinding
transition when thermal fluctuations are negligible (at low temperatures) [1].

We discuss more precisely the adhesion of graphene, in collaboration with two
experimental groups in Lyon, France [2], and in Maryland, USA [3]. We find not
only unbinding, but also a wrinkling transition. In addition, quantitative
agreement is achieved with simple models.

In the case of filaments at finite temperature[4], the pattern not only
permits a control of adhesion, it also leads to an unbinding phase transition
at finite temperatures. The dimensionality of transverse fluctuations controls
the continuity of the transition, and in some cases, re-entrant binding is
observed as temperature is increased.

[1] Adhesion of membranes and filaments on rippled surfaces,
O. Pierre-Louis, Phys. Rev. E 78, 021603 (2008)
[2] Pressure-mediated Doping in Graphene
J. Nicolle, D. Machon, P. Poncharal, O. Pierre-Louis, Alfonso San-Miguel
Nano Lett 13 043017 (2011)
[3] The princess and the pea at the nanoscale: Wrinkling and unbinding of graphene on nanoparticles
M. Yamamoto, O. Pierre-Louis, J Huang, M. Fuhrer, T.L. Einstein, W.G. Cullen..
Phys Rev X (2012)
[4] Pattern-induced thermal unbinding of filaments
O. Pierre-Louis,  Phys Rev E 83 01181 (2011).