Transition metal dichalcogenides have a layered structure and are therefore promising self-lubricating films. They can be considered as potential substitutes for carbon based films in various environmental conditions. In this work, a comparative atomic force microscopy study of co-sputtered Mo–Se–C and W–S–C films is performed to evaluate their nanotribological performances. Both films are allo...

Over the last decade, significant effort has been put into mimicking the ability of the gecko lizard to strongly and reversibly cling to surfaces, by using synthetic structures. Among these structures, mushroom-like elastomer fiber arrays have demonstrated promising performance on smooth surfaces matching the adhesive strengths obtained with the natural gecko foot-pads. It is possible to improv...

In this work, the adhesion of biomimetic polydimethylsiloxane (PDMS) pillar arrays with mushroom-shaped tips was studied on nano- and micro-rough surfaces and compared to unpatterned controls. The adhesion strength on nano-rough surfaces invariably decreased with increasing roughness, but pillar arrays retained higher adhesion strengths than unpatterned controls in all cases. The results were a...

A high fidelity delamination failure analysis was developed by combining a local failure analysis with a global fullscale finite element structural analysis to address strength and delamination failure in a single package. The methodology was demonstrated through a local threedimensional pull-off failure analysis and a geometrically nonlinear structural analysis of a five-foot composite helicop...

To compare abstract structural and lexicalist accounts of syntactic processes in sentence formulation, we examined the effectiveness of nonidiomatic and idiomatic phrasal verbs in inducing structural generalizations. Three experiments made use of a syntactic priming paradigm in which participants recalled sentences they had read in rapid serial visual presentation. Prime and target sentences co...

Abstract In this study, we investigate the effects of thermal fluctuations on generalized Johnson–Kendall–Roberts (JKR) model. We show that distribution pull-off forces in model is similar to Bradley model, and also consistent with experiment result observed Wierez-Kien et al. (Nanotechnology 29(15):155704 2018). Increasing temperature leads a broadening distribution, while reduction force. Add...

In this work the effect of substrate roughness on the adhesion of gecko foot-hair like nano structures as opposed to solid elastic materials is described and models of both synthetic nano-hairs and hair-substrate interaction are developed. First, by combining linear beam theory and geometric constraints, a nonlinear elastic model for the hair is derived. Then it is shown how for a given random ...

In this paper, the classical JKR theory of the adhesive contact of isotropic elastic spheres is extended to consider the effect of anisotropic elasticity. The contact area will then generally be non-circular, but in many cases it can reasonably be approximated by an ellipse whose dimensions are determined by imposing the energy release rate criterion at the ends of the major and minor axes. Ana...