Glenn M. Channell

Bio: Glenn M. Channell is an academic researcher from University of Illinois at Urbana–Champaign. The author has contributed to research in topics: Yield (engineering) & Rheology. The author has an hindex of 2, co-authored 2 publications receiving 225 citations.

Shear and compressive rheology of aggregated alumina suspensions

Abstract: The shear and compressive properties of aggregated alumina particles are determined as functions of volume fraction and the strength of the interparticle attraction. Over a range of volume fractions, yield stresses, τy, elastic moduli, the strain delimiting the extent of the linear elastic response, and compressive yield stress, Py, are well described by power-law functions of volume fraction, while the role of interparticle attractions can be accounted for by expressing these mechanical properties as (ϕ/ϕg − 1)n, where ϕg captures the strength of particle attractions and n the microstructure. The links between compressive and shear properties are well described by linear elastic models where the Py and τy are a function of Poisson's ratio which, for the suspensions investigated, has a value near 0.49.

Effects of microstructure on the compressive yield stress

Abstract: The effects of microstructure on the compressie properties of aggregated alumina suspensions are determined by intentionally introducing heterogeneities into the suspen- sion. Suspensions are prepared at a higholume fraction and diluted with low shear hand mixing to a series of initial concentrations. As the initial concentration is in- creased, larger heterogeneities are introduced, and the suspension becomes more com- pressible relatie to the compressie yield stress of the uniform suspension. A simple model is proposed in which the heterogeneous suspensions compress by rearrangement ( of the dense aggregates until a critical concentration f , which coincides with the c ) ¤olume fraction prior to dilution is reached. Aboe f , the suspensions consolidate c ( identically to the uniform suspension. With a single fitting parameter the size of the ) heterogeneities , the model shows semiquantitatie agreement with the experimental data.

Direct ink writing of 3D functional materials

Abstract: The ability to pattern materials in three dimensions is critical for several technological applications, including composites, microfluidics, photonics, and tissue engineering. Direct-write assembly allows one to design and rapidly fabricate materials in complex 3D shapes without the need for expensive tooling, dies, or lithographic masks. Here, recent advances in direct ink writing are reviewed with an emphasis on the push towards finer feature sizes. Opportunities and challenges associated with direct ink writing are also highlighted.

Colloidal Processing of Ceramics

Abstract: Colloidal processing of ceramics is reviewed with an emphasis on interparticle forces, suspension rheology, consolidation techniques, and drying behavior. Particular attention is given to the scientific concepts that underpin the fabrication of particulate-derived ceramic components. The complex interplay between suspension stability and its structural evolution during colloidal processing is highlighted.

Direct Ink Writing of Three‐Dimensional Ceramic Structures

Abstract: The ability to pattern ceramic materials in three dimensions (3D) is critical for structural, functional, and biomedical applications. One facile approach is direct ink writing (DIW), in which 3D structures are built layer-by-layer through the deposition of colloidal- or polymer-based inks. This approach allows one to design and rapidly fabricate ceramic materials in complex 3D shapes without the need for expensive tooling, dies, or lithographic masks. In this feature article, we present both droplet- and filament-based DIW techniques. We focus on the various ink designs and their corresponding rheological behavior, ink deposition mechanics, potential shapes and the toolpaths required, and representative examples of 3D ceramic structures assembled by each technique. The opportunities and challenges associated with DIW are also highlighted.

Colloidal inks for directed assembly of 3-D periodic structures

Abstract: Mesoscale periodic structures have been fabricated via directed assembly of colloidal inks. Concentrated colloidal gels with tailored viscoelastic properties were designed to form self-supporting f...