Journal of Bionic Engineering

May 2019, Volume 16, Issue 3, pp 400–409| Cite as

Srinadh MattaparthiChandra Shekhar SharmaEmail author

Creative & Advanced Research Based on Nanomaterials (CARBON) Laboratory, Department of Chemical EngineeringIndian Institute of Technology HyderabadKandi, TelanganaIndia

Abstract

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.

Keywords

biomimicking natural leaf replica molding non-wetting light trapping hierarchical roughness 

Full text is available at :

https://link.springer.com/article/10.1007/s42235-019-0032-5