Valeriy Luchnikov: "Self-rolling of strained polymer bilayer films: A novel route to engineering of functional microcavities"

Dr. Valeriy Luchnikov
Material Sciences Institute, Université de Haute Alsace, France

"Self-rolling of strained polymer bilayer films: A novel route to engineering of functional microcavities"

The talk is devoted to a remarkable micromechanics phenomenon observed for multilayer polymer films: self-rolling of the films in selective solvents. The rolling is due to bending moment, which is induced by unequal swelling of different layers of the film. A typical example of a self-rolling structure is a bilayer consisting of the top polystyrene (PS) and the bottom poly(4-vinyl pyridine) (P4VP) layers deposited on a solid substrate. Swelling of P4VP in acidic or alcohol solutions is opposed by the PS layer and results in curling of the film. The diameter of the arising polymer tubes can be controlled by thickness of the PS and P4VP layers, and varies between a few hundreds of nanometers and dozens of micrometers. The phenomenon provides unique possibilities for complex engineering of the inner surface of microcapillaries and tubular micro-particles. Before self-rolling, the future inner surface of a tube can be exposed to various procedures of surface functionalization like micro-contact printing, metal sputtering, photolithography, plasma treatment, etc. The engineered tubes can find advanced applications in many fields such as microfluidics, micro-electronics, optics, catalysis, etc.