Figure 1.

(a) Top: AFM topographic image of a PDL-coated PDMS-patterned surface. Bottom: line scan (cross section) along the red line shown in the AFM image. (b) Coordinate system and the definition of the angular coordinate θ. The x axis is defined as the axis perpendicular to the direction of the PDMS patterns. The directions corresponding to θ = 0, π/2, and 3π/2, and the pattern spatial period d are also shown in (a). The line scan in (a) shows that the micropatterns are periodic in the x direction with the spatial period d = 4 μm, and have a constant profile shape with a depth of approximately 0.6 μm. To see this figure in color, go online.