  We consider the response of an adsorbed polymer that is pulled by an AFM
within a simple geometric framework. We separately consider the cases of i)
fixed polymer-surface contact point, ii) sticky case where the polymer is
peeled off from the substrate, and iii) slippery case where the polymer glides
over the surface. The resultant behavior depends on the value of the surface
friction coefficient and the adsorption strength. Our resultant force profiles
in principle allow to extract both from non-equilibrium force-spectroscopic
data.
