Synthesis of artificial polymeric nanopillars for clean and reusable adhesives

We present a simple and scalable approach to fabricate nanopillars structure using combined techniques of colloidal nanolithography, and chemical etching to mimic the nanopillars of gecko foot-hairs. The resulting polymeric nanopillar structure showed nanoscopic adhesion, superhydrophobic, and easy cleaning properties. The lateral dimension of nanopillars as small as 150 nm and aspect ratio as high as 10:1 have been achieved without lateral collapse between neighboring pillars. The method allows both fabrication of synthetic structures in wafer scale area and direct integration of flexible membrane to assist the array of nanohairs in making intimate contact with the uneven surfaces. Our results indicate that a single nanohair exhibit a mean adhesive force of 1.8 nN. In the macroscopic scale, we demonstrate that the nanostructured surface can adhere firmly to a smooth glass substrate.