Figure 11
From: Deep-UV photoinduced chemical patterning at the micro- and nanoscale for directed self-assembly
Locally induced condensation of water on a chemically patterned surface. (a) A 10 μm period mask was used on an HTS surface with DUV irradiation at 30 J/cm2. The chemical patterns are thus 5 μm wide hydrophilic lines separated by 5 μm wide hydrophobic lines. Microscopy images of the same sample, under room humidity conditions (left), under increased humidity (middle), and at the initial humidity content (right). In each case, the insets correspond to the light patterns of a He:Ne laser transmitted through the sample. (b) Sample prepared with 2 irradiations (2 × 20 J/cm2) with rotation of the 5 μm period mask between the two irradiations, resulting in an array of 2.5 μm × 2.5 μm HTS hydrophobic squares separated by hydrophilic regions (SiOH). The sequence of microscopy images corresponds to increasing humidity in the atmosphere surrounding the sample. A diffraction pattern of a He:Ne laser is also given, confirming the 2D chemical patterning with good reproducibility in the x and y directions.
