Hot embossed micro-textured thin superhydrophobic Teflon FEP sheets for low ice adhesion

Abstract

Various efforts have been conducted by researchers to create synthetic superhydrophobic surfaces. However, most of these fabrication procedures are convoluted and not suitable to be applied on surfaces with complex shapes and sizes. We report a simple and low cost fabrication of a thin superhydrophobic sheet (127μm thick) of low ice adhesion strength by laser micro-texturing an aluminum master substrate followed by hot embossing on a Teflon fluoroethylene propylene (FEP) sheet for a water contact angle and roll-off angle of 160° and 4°, respectively. The micro-textured aluminum master substrate could be used multiple times to emboss the FEP sheet for a reduction in fabrication complexity and cost. The fabrication procedure also ensured that the structure of the sheet remains intact, therefore allowing it to be wrapped and adhered to target surfaces of different shapes. Ice adhesion experiment on the superhydrophobic sheet showed ice detachment strength at approximately 20kPa on average, which was <2% of the ice detachment strength of an aluminum substrate, 33% of the ice detachment strength of a smooth non-textured Teflon FEP sheet and among the lowest superhydrophobic ice adhesion strength reported in literature. Potential applications of the superhydrophobic sheet include evaporator icing control in refrigeration systems and low ice adhesion surfaces for architectural structures.