Effect of pillar aspect ratio on shear adhesion strength of hierarchical electrospun fibrous structures

This study presents a simple and effective technique for fabricating hierarchical structures for dry adhesive applications. The study employed electrospinning and post-template wetting method to fabricate hierarchical structures. This technique enabled fabrication of nanometer-sized pillars on the surface of the fibers. The shear adhesion strength of these structures was investigated using a custom-designed adhesion measurement setup attached to a tensile tester. Shear adhesion measurements were performed by sliding the samples along the glass slide. A constant preload was applied during the measurement. The obtained load versus displacement curves were then used to determine the adhesion behavior of the samples. Samples with two different aspect ratio nanopillars were used to investigate the effect of aspect ratio on the adhesion performance of the samples. The shear adhesion strength was higher for samples with higher aspect ratio nanopillars on its surface. Adhesion strength as high as 0.161 N/cm2 was obtained demonstrating their use for dry adhesive applications.