323: Interfacial switching via hydrogel–elastomer composites for dynamic topographical reconfiguration

Abstract: Mineral scaling is a major issue in wastewater treatment systems, desalination units, and heat exchangers, where deposited crystals restrict flow, block transport pathways, and reduce heat transfer efficiency. Over time, this leads to increased energy consumption, unplanned downtime, and higher maintenance costs. Stimuli-responsive interfaces provide a pathway toward surfaces that actively control interfacial phenomena rather than relying solely on static chemical or structural design. Here, we report a thermally switchable composite interface in which a poly(N-isopropylacrylamide) (PNIPAM) hydrogel layer functions as an actuation element beneath an elastomeric top film. Upon temperature switching across the lower critical solution temperature (LCST) of the hydrogel, reversible volumetric swelling and deswelling generate in-plane strain at the surface. This strain induces stretching, buckling, and microscale topographical reconfiguration of the elastomer layer. By introducing controlled mechanical deformation at the interface, this dynamic surface provides a physical strategy to disrupt mineral attachment and limit deposit stability. This approach reframes antifouling from passive resistance to active interfacial control.