Hierarchical honeycomb patterns with tunable microstructures: controllable fabrication and application as replication templates

Abstract

Here we report fabrication of hierarchically honeycomb-patterned polystyrene (PS) films with polyvinylpyrrolidone (PVP) protruded in the poresvia the combined approach of breath figure and phase separation. The simple post treatment with water washing, heating, or hot embossing is further performed to tune the microstructures of the honeycomb patterns. For example, hollow pores are obtained when the water-soluble PVP component is removed by water. The raised height of the spherical PVP protrusion in the pores can be well controlled by heating due to the heating-accelerated dewetting of the PVP from the PS bulk phase. As a universal top-down technique, hot embossing with PDMS stamps can pattern and functionalize the hierarchical pores with multi-scale surface microstructures and diverse functions simultaneously. Applying the same initial honeycomb patterns as structured templates, we have successfully fabricated a variety of well-defined morphologies of negative PDMS replicas, which are strongly dependent on the replication temperature and the post treatment.