Fig. 3. Photo-patterning results in surfaces and gel films with different characteristics. (a) Image of 10 μL water droplets on the two different sides of the patterned surface showing different wettability. (b) Prevalence of the MC state on the surface after photo-patterning indicated by the normalized intensity of the MC related ion C7H4NO3− obtained by ToF-SIMS. (c) Chemical composition of the dry gel film formed on the patterned surface obtained by creating a ToF-SIMS image using a Nap related ion (m/z 143.0, C10H7O−). (d and e) Relative intensities of the MC (C7H4NO3−) and Nap (C10H7O−) related ions on the SP and MC sides of the patterned samples extracted from the data in (b) and (c). Values are reported as mean ± standard deviation; n = 4; the * indicates statistically significant difference (2 sample t-test, DF = 3, p = 2.576 × 10−4). (f) Oscillatory nanoindentation data for the patterned hydrogel in the wet state with a 100 μm spatial resolution. The inset shows an image of the hydrogel on the patterned surface. Nanoindentation was performed in the direction of the arrow across the centre of the hydrogel. Dashed lines indicate the interface region between the Vis (SP) and UV (MC) exposed parts of the sample.
