In this work,we utilized underside of four different plant leaves with different scale of hierarchical surface roughness to fabricate large area self-cleaning antireflective polymer surfaces.A simple and precise two-step soft-lithography replica molding technique was deployed by using polydimethylsiloxane (PDMS) polymer as a replicating material.In the first step,a negative PDMS replica was fabricated by using the underside of an original leaf as a template material.In the second step,a positive PDMS replica was fabricated through a negative PDMS replica used as a template.In order to study the non-wetting and light trapping properties,as-replicated polymer surfaces were characterized using Scanning Electron Microscopy (SEM),contact angle goniometer,and UV-Vis spectroscopy.SEM images confirmed the successful replication of complex hierarchical structures while contact angle measurement studies established retaining high non-wetting properties in polymer replicas.Optical studies suggest near zero reflection in normal mode and less than 5% diffuse reflection when measured using integrated sphere mode.These results have been correlated and explained with the air-liquid fraction and roughness factor as measured using three-dimensional optical profilometer.
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