Modeling of the detachment of a molecule from a surface: Illustration of the “Bell–Evans effect”

Issue title: Selected papers of the Euromech Colloquium No. 420, Mechanobiology of Cells and Tissues

Article type: Research Article

Authors: Hemmerlé, J. | Picart, C. | Gergely, C. | Schaaf, P. | Stoltz, J.‐F. | Voegel, J.‐C. | Senger, B.^;

Affiliations: Institut National de la Santé et de la Recherche Médicale, Unité 424, UFR d'Odontologie, Université Louis Pasteur, 11, rue Humann, 67085 Strasbourg Cedex, France | Institut Charles Sadron, Centre National de la Recherche Scientifique, Université Louis Pasteur, 6, rue Boussingault, 67083 Strasbourg Cedex, France | Mécanique et Ingénierie Cellulaire et Tissulaire, UMR 7563, Centre National de la Recherche Scientifique, Faculté de Médecine, BP 184, 54505 Vandoeuvre‐lès‐Nancy Cedex, France

Note: [] Address for correspondence: B. Senger, INSERM U.424‐11, rue Humann, 67085 Strasbourg Cedex, France. Tel.: +33 390 243 258; Fax: +33 390 243 379; E‐mail: [email protected]‐strasbg.fr.

Abstract: This article deals with the modeling of the detachment of a molecule initially adsorbed on a surface and submitted to an external force whose strength increases with time. By means of an atomic force microscope (AFM), it is possible to measure the force when the molecule separates from the substrate. However, it is known that this force depends to a large extend on the rate at which the pulling force is applied (“Bell–Evans effect”). Two models are described to illustrate this behavior. First, a random walk approach is suggested to reveal the fundamental principle of the escape over a time‐dependent energy barrier. Second, a multi bead‐and‐spring model is proposed to mimic the AFM experiment and numerical simulations, based on Brownian dynamics, are performed.

Journal: Biorheology, vol. 40, no. 1-3, pp. 149-160, 2003