Surface Micro-Structuring Using Polymer Elongation
High-aspect structures are fabricated by photo-polymer elongation using a template. The template, tungsten wire of sub-mm diameter, makes SU-8 film locally stretched and deformed in long and fine fibrous geometry. The aspect ratio of fabricated structure becomes over 8, while the finest diameter is less than 10μm. Both of surface tension and viscosity of SU-8 film determines the yield of fibrous micro-structure. The wire diameter and drawing distance allow one to obtain desired profile of structure. Fibrous structures can be hexagonally aligned utilizing appropriate template with specific diameter and pitch of wire designed based on an analysis of surface energy.
Jianhong Zhao, Masanori Kunieda, Guilin Yang and Xue-Ming Yuan
A. Kaneko et al., "Surface Micro-Structuring Using Polymer Elongation", Key Engineering Materials, Vols. 447-448, pp. 685-689, 2010