Miniaturization of Patterns Formed in Non-Homogeneous Soft Thin Film

Author(s): Sunita Singh

We are focused to find different techniques to create,miniaturized patterns on such soft interfaces to enhance surface properties like hydrophobicity, adhesiveness, optical and catalytic. In the present work, we study the instability and morphology of a thin incompressible, inhomogeneous elastic soft film, whose shear modulus is exponential function or arbitrary function of film thickness. A LSA (linear stability analysis) has been done to obtain the minimum stress or force required to perturb the top surface of the film. In our study we obtained the smaller length scale features can be formed at the interface in these anisotropic (nonhomogeneous) materials where the anisotropy exists only in the normal direction. The present work constituted the range of length scale of instability is 0.3h<λ<2.96, lower critical stiffness from LSA and total energy minimization, to look out the evolved morphology with high aspect ratio at the interface of film and contactor. Similar length scale of instability can be obtained using different techniques like patterned substrates and bilayers where it was possible to decrease the length scale by about an order of magnitude than those formed in simple elastic thin films because of antagonistic energies (elastic and interaction) present.