Artificial asymmetric lipid membranes at planar interfaces

Surface-sensitive techniques have long been pivotal in probing the structure of lipid bilayers, providing deep insights into their composition and behaviour. These methods have then evolved to address the challenge of studying asymmetric lipid membranes at solid-liquid and liquid-liquid planar interfaces. This chapter reviews recent progress in this field, focusing on the development of experimental approaches that enable the creation of planar bilayers with differing compositions in their outer and inner leaflets. By presenting the results of these studies and describing the innovative techniques and sample preparation methods developed over the past two decades, we highlight how these developments contribute to our understanding of two-dimensional lipid systems and their applications in mimicking bacterial and mammalian cell membranes.