Micropatterning of hybrid polydimethylsiloxane for replica leaves

Artificial surfaces representing key features of plant leaves, such as surface topography and nutrient availability, promise to play an important role in phyllosphere microbiology. While polydimethylsiloxane (PDMS) constitutes an ideal candidate for leaf replica materials, its inherent hydrophobicity limits the diffusion of aqueous liquids. To solve this, we added superabsorbent polymer fillers Carbopol® and Permulen TM to PDMS, to increase the diffusion of aqueous liquids. We demonstrate that hybrid PDMS retains its capability to resolve leaf microstructures, while exhibiting similar contact angles to PDMS and the abaxial surface of Arabidopsis thaliana leaves. Water diffusion and mass flow through hybrid PDMS membranes were consistently higher than PDMS over the 144 h experimental duration. In addition, bacteria distribution patterns on hybrid PDMS were similar to those observed on A . thaliana leaves. However, the patterns observed on hybrid PDMS appeared to be influenced by the increase in wettability. These findings demonstrate that hybrid PDMS replicas can be used as an artificial surface to study bacterial behavior and microbe-microbe interactions.