Achieving control of membrane shape and topology is of crucial importance t
o regulate function and performance of many systems in the realms of biolog
y, physics, and chemical sciences. The design of a kit of versatile microsc
opic tools for tuning the shapes of fluid membranes relies ultimately on th
e possibility of tailoring molecules for applying a given, well-chosen forc
e, to the self-assembled interfaces. Here we discuss theoretically the abil
ity of grafted polymers to perform as mesoscopic pressure patches. We compu
te the pressure that a grafted polymer applies to the supporting surface. W
e also show that this entropic pressure leads to a well-defined pinched for
m of the membranes. Moreover. new membrane-mediated forces result from the
action of these pressure tools, enabling action upon their spatial distribu
tion along the membrane surface.