Tear-off versus global existence for a structured model of adhesion mediated by transient elastic linkages

We consider a microscopic model for friction mediated by transient elastic linkages introduced in [V. Milisic and D. Oelz. SIAM J. on Math. Anal. (2015). V. Milisic and D. Oelz. J. Math. Pures Appl. (2011)]. In the present study we prove existence and uniqueness of a solution to the coupled system under weaker hypotheses. The theory we present covers the case where the off-rate of linkages is unbounded but increasing at most linearly with respect to the mechanical load. The time of existence is typically bounded and corresponds to tear-off where the moving binding site does not have any bonds with the substrate. However, under additional assumptions on the external force we prove global in time existence of a solution that consequently stays attached to the substrate.