Self‐Cleaning Sensor Surfaces for Long‐Term Environmental Monitoring

Monitoring forest ecosystems requires outdoor sensors capable of long‐term operation throughout an entire growing season. They must remain protected against dust and pollen without any human intervention. This article presents a novel self‐cleaning and antibiofouling surface for cuvettes connected to leaf‐attached gas sensors using a combination of nanoparticles and C─H insertion crosslinking (CHic). Specifically, a solution containing trimethylsilyl‐functionalized silica nanoparticles (NPs) and a perfluoroacrylate (PFA) copolymer with integrated photoreactive benzophenone (BP) moieties is spray‐coated onto the substrate surfaces. Upon UV irradiation, the dormant BP moieties become activated and react with nearby C─H groups via C─H insertion leading to crosslinking of the coating layer. Simultaneously, reactions occur with C─H groups present in the polymer substrate, leading to covalent attachment of the network to the cuvette surface, and between the polymer network and the NPs, so that all reactions are performed within a single process step. Covalent bonds established by the CHic process provide strong adhesion and enhanced stability of the generated superhydrophobic coating to the cuvette surface. Finally, the cuvettes were attached to tree leaves and exposed to outdoor forest environments, where they exhibited efficient self‐cleaning behavior. The coatings demonstrated robust antisoiling and antibiofouling performance over a whole vegetation period in the forest.