Programmable self-assembly of microstructures on mimicked three dimensional functional surfaces

Abstract

Capillary force has been extensively investigated to drive the construction of complex microstructures, though most of those previous self-assembled microstructures were on flat surfaces. In this study, we propose a capillary-force-driven self-assembly strategy working for bionic three-dimensional (3D) functional surfaces. Precisely printed micropillar arrays with an extremely large format using projection micro-stereolithography (PμSL) 3D printing technique are assembled into periodic layered structures with the assistance of ethanol evaporation induced capillary force, though the capillary-force-driven self-assembly micropillars are strongly depend on their spatial arrangement and geometric parameters. Also, large-scale programmable capillary-force-driven self-assembly of micropillars can be achieved by tailoring the arrangements of them for various patterns. We further demonstrate the functions of programmable self-assembly micropillars for the selective capture and release of microparticles. Most significantly, we extend the programmable capillary-force-driven self-assembly of micropillars on 3D bionic curved surfaces with various applications, including the mimicked patterns and selective capturing of microparticles.