Pressure patches for membranes: The induced pinch of a grafted polymer

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.