Processing multimodal information with structure via prewetting phase transitions

Biological membranes & polymers are rich, multi-component surfaces that process environmental information presented through molecular concentrations, such as those of ligands and transcription factors. These biological surfaces exhibit thermodynamic phase transitions: liquid de-mixing transitions in the case of membranes, and configurational phase transitions in the case of polymers. As a result, when such a surface interacts with a complex three-dimensional fluid, the phase behavior of the surface and bulk become coupled, for instance in terms of a prewetting transition where localized de-mixing of the bulk coincides with a surface phase transition. Here we describe how, due to this coupling, surface phase behavior can be used as readout of bulk mixture properties. Using Landau theory and Monte-Carlo simulations, we argue that vicinity to critical points and the prewetting transition allows for sensitive comparison of bulk components and simple logical operations. Furthermore, the inclusion of emergent spatial structure expands the types of measurements accessible to these systems and permits higher-order comparisons. These measurements might be relevant for coordination of gene expression in the case of multicomponent polymers and to interface arrangements in the case of membranes.