| 초록 |
Buckling of thin rigid films placed on elastomeric substrates such as polydimethylsiloxane (PDMS) is a well-known phenomenon in the buckling instability originating from the moduli mismatch between a substrate and a thin film placed at the top. Recently, many studies on the microstructure created by the buckling have been reported but most of the work has focused on mechanically homogeneous thin films, such as simple metal, semiconductor or polymeric thin films. Here, we present the buckling of mechanically heterogeneous thin films such as patterned polystyrene (PS) or oriented block copolymer (BCP) films placed on top of PDMS substrates, resulting in hierarchical structures. Resulting buckled structure showed the structural change depending on the alignment of anisotropically patterned top films with respect to the buckled direction. We believe that this work could lay a foundation for a new patterning technique which combines both nano- and micro-sized patterns at a time. |
