Membrane Transport, Molecular Machines, and Maxwell's Demon

The spontaneous generation of transmembrane gradients is an important fundamental research goal for artificial nanotechnology. The active transport processes that give rise to such gradients directly mirror the famous Maxwell's Demon thought experiment, where a Demon partitions particles between two chambers to generate a nonequilibrium state. Despite these similarities, discussion of Maxwell's Demon is absent in the literature on artificial membrane transport. By contrast, the emergence of rational design principles for nonequilibrium artificial molecular motors can trace its intellectual roots directly to this famous thought experiment. This perspective highlights the links between Maxwell's Demon and nonequilibrium machines, and argues that understanding the implications of this 19th century thought experiment is crucial to the future development of transmembrane active transport processes. The Maxwell's Demon thought experiment creates nonequilibrium gradients, and underpins the molecular ratchet mechanisms that drive artificial motors and pumps. Lipid bilayers form membranes that closely mirror the compartments of Maxwell's Demon. This Concept Article addresses how ratchet mechanisms might be translated from the field of small‐molecule machines to create artificial transmembrane pumps.