title: Squeezing instabilities and delamination in elastic bilayers: a linear stability analysis.
abstract: A linear stability analysis is presented to understand the instabilities that arise in an elastic bilayer, consisting of a very thin bottom layer (thickness < 100 nm) that acts as a wetting film and a top layer that acts as an adhesive film, when placed in contact proximity with an external rigid contactor. Depending on whichever layer is more compliant, "squeezing modes" of instability with a variety of length scales ranging from <<3h to <<3h (h: bilayer thickness) are found to be possible. The least length scales obtained are 0.1h. The squeezing instabilities are, however, accompanied by delamination of the film-film interface. The instability length scales, the strength of interactions required, and the delamination decrease as the compliance of the top film increases. Surface tension effects are found to have a stabilizing influence which increases the instability length scales and decreases the degree of delamination at the cost of high interaction penalty.
authors.affiliation: Department of Chemical Engineering, Indian Institute of Technology Delhi, New Delhi 110 016, India.
authors.forename: Hemalatha
authors.initials: H
authors.lastname: Annepu
authors.forename: Jayati
authors.initials: J
authors.lastname: Sarkar
mesh_terms: D003198:Computer Simulation; D055119:Elastic Modulus; D016014:Linear Models; D008051:Lipid Bilayers / Q000737:chemistry*; D008567:Membranes, Artificial; D008956:Models, Chemical; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D013314:Stress, Mechanical; D017155:Wettability
chemical_list: D008051:Lipid Bilayers; D008567:Membranes, Artificial