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A new Tabor's parameter ? is defined for adhesion-delamination of thin membranes. A small ? corresponds to a thick, small, and stiff membrane under the influence of a long-range weak surface force, as in the Derjaguin-Muller-Toporov (DMT) limit. A large ? corresponds to a thin, large, and flexible membrane under the influence of a short-range strong surface force, as in the Johnson-Kendall-Roberts (JKR) limit. A new adhesion map based on ? is drawn to summarize the "pull-off" events and the delamination trajectory for membranes under mixed stretching-bending deformation. Maps are generated for one- and two-dimensional membranes clamped at the edge. [ABSTRACT FROM AUTHOR]

The mechanical deformation of an ideal thin-walled cylindrical shell is investigated in the presence of intersurface interactions with a planar rigid substrate. A Dugdale- Barenblatt-Maugis (DBM) cohesive zone approximation is introduced to simulate the convoluted surface force potential. Without loss of generality, the repulsive component of the surface forces is approximated by a linear soft-repulsion, and the attractive component is described by two essential variables, namely, surface force range and magnitude, which are allowed to vary. The nonlinear problem is solved numerically to generate the pressure distribution within the contact, the deformed membrane profiles, and the adhesion-delamination mechanics, which are distinctly different from the classical solid cylinder adhesion models. The model has wide applications in cell adhesion and nanostructures. [ABSTRACT FROM AUTHOR]

A nano-cheese-cutter is fabricated to directly measure the adhesion between two freestanding nano-fibers. A single electrospun fiber is attached to the free end of an atomic force microscope cantilever, while a similar fiber is similarly prepared on a mica substrate in an orthogonal direction. External load is applied to deform the two fibers into complementary V-shapes, and the force measurement allows the elastic modulus to be determined. At a critical tensile load, 'pull-off' occurs when the adhering fibers spontaneously detach from each other, yielding the interfacial adhesion energy. Loading-unloading cycles are performed to investigate repeated adhesion-detachment and surface degradation. [ABSTRACT FROM AUTHOR]