Supplementary Material (ESI) for Lab on a Chip This journal is © The Royal Society of Chemistry 2011

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SUPPORTING INFORMATION

Fabrication of high-aspect-ratio polymer microstructures and hierarchical textures using carbon

nanotube composite master molds

Davor Copic,a Sei Jin Park,a Sameh Tawfick,a Michael F.L. De Voldera,b and A. John Hart*a

a Department of Mechanical Engineering, University of Michigan, 2350 Hayward Street, Ann Arbor, MI 48109-2125 USA Tel: +1.734.615.6146; E-mail: ajohnh@umich.edu b IMEC, Kapeldreef 75, 3001 Heverlee, Belgium and KULeuven, Celestijnenlaan 300B, 3000 Leuven, Belgium Comparision of as-grown and densified CNT micropillars

Fig. S1. SEM images of: (a) as-grown CNT micropillar and (b) closeup of top edge area; (c) densified CNT micropillar (before SU-8 infiltration) and (d) corresponding closeup. Note that the distinct random (top surface) and aligned (sidewall surface) textures that appear in the densified structure are captured in the master (Fig. 2a) as well.

Supplementary Material (ESI) for Lab on a Chip This journal is © The Royal Society of Chemistry 2011

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Model of capillary wicking during the master formation step

Fig S2. Predicted relationship between steady-state height of capillary rise within an individual CNT micropillar, compared to the space between a pair of CNT micropillars.

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Liquid inside pillar

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