Living cells are enveloped in an ultra thin (similar to 6 nm) membrane whic
h consists basically of a bi-molecular film of lipid molecules in which are
embedded functional proteins that perform a variety of functions, includin
g energy transduction, signalling, transport of ions (and other molecules)
etc., and also acts as a diffusion barrier between the cell interior (cytop
lasm) and the external medium. A simple statistical mechanical analysis of
the self-assembly of the membrane from its components provides useful insig
hts into the molecular organisation of the membrane and its electrical prop
erties. The stability of the structure is also closely connected to its ele
ctrical properties and this has provided not only a useful tool for fundame
ntal research but has spawned also applications, some of which have had a m
ajor impact in biomedical research acid are now being exploited commerciall
y. An overview is given of the rapid progress made in our understanding of
the physics of both the molecular organisation and function of cell membran
es and some of the fascinating and socially and commercially important appl
ications that have flowed from this.