(81e) Chaotic Thermal Convection in Microfluidic Hydrothermal Pore Environments

A key unanswered question in the origin of life involves elucidating how complex macromolecules spontaneously emerged from elementary building blocks present at extremely dilute concentrations in the prebiotic ocean. Pore networks permeating mineral formations near undersea hydrothermal vents have emerged as potential hot spots for these kinds of biochemical processes, fueled by the recent discovery of Earth’s oldest microfossils in hydrothermal systems and the existence of similar environments under the icy surface of Saturn’s moon Enceladus. Here we explore how thermally-actuated flows that naturally occur within these micro-scale pore spaces display surprisingly complex 3D chaotic characteristics that can enable continuous transport of particulate and molecular species from the bulk fluid to discrete targeted locations along interfacial boundaries. Using coordinated simulations and experiments, we find that these flows are capable of accelerating transport to the surface by several orders of magnitude under hydrothermally relevant conditions. We also explore partitioning and assembly of macromolecular species into membrane-like films capable of maintaining localized pH gradients. These results suggest that microscale chaotic thermal convection may supply a previously unappreciated mechanism to explain prebiotic surface-catalyzed processes and establishment of early bioenergetic pathways central to the origin of life.