Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 4 of 4
Full-Text Articles in Engineering
Extreme Indentation And Fracture Of Soft Polymer Gels, Shruti Rattan
Extreme Indentation And Fracture Of Soft Polymer Gels, Shruti Rattan
Doctoral Dissertations
The mechanical properties of conventional hard materials, such as metals and ceramics, have received widespread attention in the past several decades; however mechanical characterization, failure in particular, of soft materials, such as polymer gels, elastomers, and biological tissues and organs, has largely been ignored. While practical issues such as difficulty in handling, processing, and slippage offer complexities in characterization, the breakdown of the fundamental assumptions of linear elastic fracture mechanics due to large strains prior to failure, significant energy dissipation ahead of a crack tip and rate and time dependent effects makes understanding of failure in soft materials even more …
Ultra-Thin Polymer Films And Hierarchical Composites: Processing And Mechanical Properties, Yujie Liu
Ultra-Thin Polymer Films And Hierarchical Composites: Processing And Mechanical Properties, Yujie Liu
Doctoral Dissertations
Properties and fabrications of ultra-thin polymer films and hierarchical composites are of great interest in packaging, electronics, separations, and other manufacturing fields. However, due to the inherently fragile nature of ultra-thin polymer films, measuring their properties has proven difficult. Additionally, variables controlling thin polymer patterns (e.g. substrate wetting property) and composites (weight percent of particulates in matrix) formation have not been fundamentally well understood. Within this spectrum, fundamental understanding of formation mechanisms of these patterns and composites are needed. Additionally, a new characterization technique is required to be able to measure the mechanical properties of fabricated composites and thin films. …
Cavitation And Puncture For Mechanical Measurement Of Soft Solids, Sami Fakhouri
Cavitation And Puncture For Mechanical Measurement Of Soft Solids, Sami Fakhouri
Doctoral Dissertations
Gels and other soft elastic networks are a ubiquitous and important class of materials whose unique properties enable special behavior, but generally elude characterization due to the inherent difficulty in manipulating them. This work focuses on understanding and utilizing large, local deformation and failure in soft solids for characterization of the mechanical properties of otherwise inaccessible or nonmanipulable materials. Cavitation Rheology (CR), a pioneering mechanical measurement technique in this regard, where local material failure is imposed and monitored at the tip of a pressurized needle, serves a central role in this thesis. First, CR is used to make in vivo …
Mechanics Of Hydrogels And Biological Tissues, Jessica A. Zimberlin
Mechanics Of Hydrogels And Biological Tissues, Jessica A. Zimberlin
Open Access Dissertations
The relationship between cells and their environment is one of dynamic reciprocity, whereby cells can influence their surrounding and the surroundings can influence the cells. One example of this relationship arises from the effect of the mechanical properties of an environment on a cell and of a cell on its environment. Inspired by this relationship, we investigate 1) the local environment of biological materials, both native and synthetic, and 2) the forces that cell sheets exert on surfaces. We do this by developing techniques that focus on local mechanical properties and experimental strategies that provide insight into intercellular mechanics. We …