The assembly of soft biofunctionalized and biocompatible interfaces on solids by deposition of ultrathin soft polymer films, supported lipid/protein bilayers or membranes separated from solids by soft polymer cushions are described and their potential scientific and practical applications are summarized. The former include the immobilization of membrane receptors or proteins and polysaccharides of the extracellular matrix in order to apply surface sensitive techniques to the study of protein-protein recognition processes at membranes or the interplay of specific and universal interfacial forces during cell adhesion, locomotion or proliferation.