We have developed a Self-assembled floating supported membrane sample system comprised of unsaturated phospholipid bilayers held ~1nm from a PEGylated charged alkane thiol SAM through an interplay of weak attractive and strong repulsive forces. Here, building on previous results we wish to gain an understanding of the wider factors governing this sample type and its application in structural and biophysical studies. In particular the factors effecting the SAM-to-bilayer distance and role of cations in this sample system. In the proposed research activities, and through a comparing three differing bilayer types deposited onto three differing SAMs, we wish to examine the how an increase in anionic lipids changes the behaviour of these samples under differing solution conditions and examine the effect of changing the level of PEGylation and charge on the SAM surface.