Fabrication and analysis of enforced dry adhesives with core-shell micropillars

Abstract

We present a simple method for fabricating robust dry adhesives by coating a soft polydimethyl siloxane (PDMS) thin layer on rigid backbone micropillars of polyurethane acrylate (PUA). These core-shell type micropillars demonstrated enhanced durability both in normal and shear adhesion over more than 100 cycles of attachment and detachment. Relatively strong normal (∼11.4 N cm -2) and shear (∼15.3 N cm-2) adhesion forces were observed, which were similar to or even larger than those of homogeneous PDMS micropillars. A simple theoretical model based on beam deflection theory was used to explain the experimental results.