  Forced detachment of a single polymer chain, strongly-adsorbed on a solid
substrate, is investigated by two complementary methods: a coarse-grained
analytical dynamical model, based on the Onsager stochastic equation, and
Molecular Dynamics (MD) simulations with Langevin thermostat. The suggested
approach makes it possible to go beyond the limitations of the conventional
Bell-Evans model. We observe a series of characteristic force spikes when the
pulling force is measured against the cantilever displacement during detachment
at constant velocity $v_c$ (displacement control mode) and find that the
average magnitude of this force increases as $v_c$ grows. The probability
distributions of the pulling force and the end-monomer distance from the
surface at the moment of final detachment are investigated for different
adsorption energy $\epsilon$ and pulling velocity $v_c$. Our extensive
MD-simulations validate and support the main theoretical findings. Moreover,
the simulation reveals a novel behavior: for a strong-friction and massive
cantilever the force spikes pattern is smeared out at large $v_c$. As a
challenging task for experimental bio-polymers sequencing in future we suggest
the fabrication of stiff, super-light, nanometer-sized AFM probe.
