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Full-Text Articles in Engineering
Why Should We Care About Buckling?, Alfred Crosby
Contact-Line Mechanics For Pattern Control, Guillaume Miquelard-Garnier, Andrew B. Croll, Chelsea S. Davis, Alfred Crosby
Contact-Line Mechanics For Pattern Control, Guillaume Miquelard-Garnier, Andrew B. Croll, Chelsea S. Davis, Alfred Crosby
Alfred Crosby
Wrinkled surfaces are ubiquitous in Nature and can be used in a large range of applications such as improved adhesives, microfluidic patterns, or as metrology instruments. Despite wide-ranging applications, existing methods do not permit local pattern control since all existing methods impose extensive compressive strains. In this article, we describe a new process that exploits the local deformation of a soft substrate as it stretches to form an adhesive interface with a thin polymer film. The wrinkle pattern is effectively a measurement of the strain-field created during the adhesion process, which shows a strong dependence on the speed of attachment. …
Draping Films: A Wrinkle To Fold Transition, Alfred Crosby, D. P. Holmes
Draping Films: A Wrinkle To Fold Transition, Alfred Crosby, D. P. Holmes
Alfred Crosby
A polymer film draping over a point of contact will wrinkle due to the strain imposed by the underlying substrate. The wrinkle wavelength is dictated by a balance of material properties and geometry; most directly the thickness of the draping film. At a critical strain, the stress in the film will localize, causing hundreds of wrinkles to collapse into several discrete folds. In this Letter, we examine the deformation of an axisymmetric sheet and quantify the force required to generate a fold. We observe that the energy of formation for a single fold scales nearly linearly with the film thickness. …
Cavitation Rheology Of The Vitreous: Mechanical Properties Of Biological Tissue, Jessica A. Zimberlin, Jennifer J. Mcmanus, Alfred Crosby
Cavitation Rheology Of The Vitreous: Mechanical Properties Of Biological Tissue, Jessica A. Zimberlin, Jennifer J. Mcmanus, Alfred Crosby
Alfred Crosby
We demonstrate the importance of measuring the mechanical properties of biological tissue in vivo by quantifying the mechanical properties of bovine vitreous both in its native state and upon removal from the eye. The mechanical properties are determined by the cavitation rheology technique developed in our labs to determine the linear modulus. This technique involves inducing a cavitation event at the tip of a syringe that is located at an arbitrary location within the vitreous sample. The pressure at which the cavitation event occurs can be directly related to the modulus. We show that the modulus decreases upon removal of …