A cluster of N ligand-receptor pairs between two parallel surfaces under an applied force F=Γt with a constant loading rate Γ is considered. Our theoretical and numerical studies show that there is a characteristic force fc and a characteristic loading rate Γc. At Γ<Γc, the mean rupture force Fr of the cluster is close to but lower than Nfc. In this regime, cluster dissociation can be modeled as a one-dimensional barrier crossing process and Fr scales like Nfc-Fr-N1 /3[ln(Γc/Γ)]2/3. At Γ=Γc, the cluster dissociation occurs at F r=Nfc. At ΓΓc, Fr for clusters with large N is well predicted by the rate equation because the fluctuations of the number of closed bonds are unimportant. Our study shows that fc and Γc are important emergent properties for understanding the mechanical response of adhesion clusters.
|Journal||Physical Review E - Statistical, Nonlinear, and Soft Matter Physics|
|State||Published - 16 Jun 2011|