This paper reports a simple and flexible method for generating hierarchical patterns from wrinkling instability. Complex features with gradually changing topographies are generated by using the spontaneous wrinkling of a rigid membrane (titanium) on a soft foundation (polystyrene) compressed via the diffusion of a solvent. We show that the morphology of these unreported wrinkled patterns is dir...

* Please send all correspondence to: T. Meinders, University of Twente, Mechanical Engineering Department, Po Box 217, 7500 AE Enschede, The Netherlands. ABSTRACT: Hutchinson approach has been successfully used by a number of researchers in thin sheet metal forming processes for wrinkling prediction. However, Hutchinson approach is limited to regions of the sheet that are free of any contact. T...

Complex textured surfaces occur in nature and industry, from fingerprints to lithography-based micropatterns. Wrinkling by confinement an incompatible substrate is attractive way of generating reconfigurable patterned topographies, but controlling the often asymmetric apparently stochastic wrinkles that result remains elusive goal. Here, we describe a new approach understanding confined elastic...

A ubiquitous motif in nature is the self-similar hierarchical buckling of a thin lamina near its margins. This seen leaves, flowers, fungi, corals, and marine invertebrates. We investigate this morphology from perspective non-Euclidean plate theory. identify novel type defect, branch-point normal map, that allows for generation such complex wrinkling patterns elastic hyperbolic surfaces, even a...

Interfaces are ubiquitous in nature and absolutely key for life as illustrated by such complex interfaces as the cell membrane and the endothelial and epithelial linings of tissues. The mechanical properties of these interfaces play an important role in their biological functions. In this highlight, we describe our recent work (Pocivavsek et al., Science, 2008, 320, 912) using geometry as a too...

Women appear to be at greater risk of developing wrinkles with age than men. To evaluate the effect of pregnancy and menopause on facial wrinkling, a total of 186 Korean women volunteers aged between 20 and 89 years were interviewed for information on menstrual and reproductive factors. An 8-point photographic scale developed for assessing the severity of wrinkles in Asian skin was used. Cumula...

The role of substrate nonlinearity in the stability of wrinkling of thin films bonded to compliant substrates is investigated within the initial post-bifurcation range when wrinkling first emerges. A fully nonlinear neo-Hookean bilayer composed of a thin film on a deep substrate is analysed for a wide range of the film-substrate stiffness ratio, from films that are very stiff compared with the ...

Graphene was dispersed using a tip sonicator and the effect of surfactants were analysed. Sodium Dodecyl Sulphate (SDS) and Polyvinyl Alcohol (PVA) were compared to observe whether or not they had any effect on any de-wrinkling, and secondly whether they aided to achieve better dispersions. There is a huge demand for wrinkle free graphene as this will greatly increase its usefulness in various ...

Symmetry-breaking transitions associated with the buckling and folding of curved multilayered surfaces-which are common to a wide range of systems and processes such as embryogenesis, tissue differentiation and structure formation in heterogeneous thin films or on planetary surfaces-have been characterized experimentally. Yet owing to the nonlinearity of the underlying stretching and bending fo...

Various mechanisms have been argued for skin wrinkling, one of the hallmarks of aging. We hypothesize that chronic sympathetic bias is a previously unrecognized mechanism for wrinkling. In the acute setting of water immersion, reversible skin wrinkling is a well-known reflex mediated by the autonomic nervous system. We postulate that skin wrinkling results as a local maladaptive manifestation o...