| In recent years, increasing interest has been focused on the preparation ofordered wrinkles on the surface of the multilayers that are coated on thepolydimethylsiloxane (PDMS) substrate. However, the methods that are utilized toprepare the selective wrinkles are complicated. And fine control over the periodicityand orientation of the wrinkles has not been involved. In this thesis, we pay attentionto how to fabricate multilayers on the selectively-exposed PDMS when it is in thenon-strained/strained state, and how to induce the selective surface wrinkling.In the first part, the strain-free PDMS is exposed to oxygen plasma (OP) viadifferent meshes of copper grids, followed by transfer of PS film or sputteringdeposition of Pt film on its surface. Subsequently, thermal annealing is utilized toinduce the surface wrinkling on the composite system. The influence of theexperimental factors on the resulting morphologies has been studied. They include theduration of OP exposure, the thickness of PS/Pt film, and the mesh of the appliedcopper grid.In the second part, the uniaxially-strained PDMS is subjected to the selective OPexposure via copper grid, followed by the full release of the pre-strain. In the latersteps, the same procedure such as the crust deposition and the heating-inducedwrinkling is carried out.The obtained results show that the selective surface wrinkling has been realized.For example, in the first part, we can control the heating temperature to control whichregion (i.e.,, the exposed and non-exposed area) to selectively wrinkle. In the secondpart, the highly aligned wrinkling patterns are formed in the selectively-exposedregion. They act as the well-defined boundary to induce the subsequently heating-induced wrinkles in the non-exposed region, which are highly oriented perpendicularto the boundary. Here the wavelengths of the well-organized orthogonal wrinkles canbe independently tailored via the exposure duration and the additionally depositedfilm thickness. |
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