Deep eutectic solvents (DES) and ionic liquids (ILs) are often amphiphilic and interact with phospholipid membranes. Mixtures between choline and gernanic acid, coined 'CAGE', have been found to facilitate the transdermal delivery of larger pharmaceuticals, such as insulin. However, little is known about its mechanism of activity. The purpose for obtaining this data was to characterise aqueous suspensions of choline and germanic acid (CAGE) and choline and octanoic acid (CAOT) and compare their interactions with solid-supported lipid bilayers and vesicle layers. Particularly, dynamic light scattering (DLS) and quartz crystal microbalance with dissipation (QCM-D) measurements were used alongside neutron reflectivity (NR) to evaluate any structure-function relationships contributing to the DES behaviour, aiming towards the rational design of neoteric solvents for transdermal delivery.