Fig. 5: Soft photomask resolves curved, rough and defect surfaces.

a Photograph of PET substrate on a curvilinear Teflon surface. b–g SEM images of the photoresist patterns at the three points (b, d, f) indicated in (a). The upper panel images show images with lower magnification, and the lower panel images with higher magnification. Scale bars: 1 μm for (b, f), 5 μm for (d). h Photograph of leaf-shaped PDMS as a substrate. The inset shows a photograph of a real leaf that was used as molding template. i, j Optical microscopy images of photoresist features on the parts of the substrate indicated with red dotted rectangles in exhibiting continuous (i) and discrete (j) surfaces. Scale bars: 50 μm. k–n SEM images of photoresist dot pattern on the continuous (k) and discrete (l) surfaces. m, n Show magnified images of (k) and (l), respectively, of the part of the surface as indicated by red dotted rectangles. Scale bars: 25 μm for (k, l), 1 μm for (m), 2 μm for (n). o, p AFM images of the continuous (o) and discrete (p) parts of the surfaces as indicated by red dotted rectangles in (i, j). q Schematic illustration of a soft substrate on a surface with step, curl and kink defects. r–t SEM images of photoresist dot feature at kink (r), step (s) and curl (t) on a surface. Scale bars: 1 μm for (r, s), 2 μm for (t).