Micropatterns based on deformation of a viscoelastic honeycomb mesh

We report that various geometric patterns can be formed upon mechanical deformation of hexagonal micro polymer mesh. The patterning of micromesh can be applied to the fabrication of micropatterned soft-materials for cell culturing. A microporous film was prepared from a viscoelastic polymer, poly(epsilon-caprolactone). The film was a hexagonal mesh of 4 mum diameter. Plastic deformation of the film was caused by loading tensile force in one direction. Geometrical patterns such as elongated hexagons, rectangles, squares, and triangles were found in the stretched microporous film. These four types of deformation were reproduced by computer simulations using a viscoelastic network of hexagonally connected viscoelastic bonds. On the stretched hexagonal mesh, cardiac myocytes formed fibrous tissue where cells were aligned along the direction of the long axis of micropores. The hierarchical structure of blood vessels could be modeled by the coculture of endothelial cells and smooth muscle cells using a stretched honeycomb film as a micropatterned substrate.