Every year The American Society of Mechanical Engineers (ASME) hosts the International Mechanical Engineering Congress & Exposition (IMECE) conference, where those in the mechanical engineering field can gather to share their research and findings. This past year, senior mechanical engineering students Adam Novotny and Christopher Stabile had the opportunity to present their work at IMECE 2017 in Tampa, FL.
Adam Novotny showcased work entitled Numerical Analysis on the Influence of Taper Junction Corrosion Profile With Emphasis on Ti-Alloy Modular Hip Arthroplasty, while Christopher Stabile presented his work on Stochastic Simulation of Diffusive Behavior of Macromolecules Encapsulated in Electrospun Fibers: A Parametric Study. Below are the abstracts. Adam worked on his research with mechanical engineering chair, Manish Paliwal, while Christopher worked with mechanical engineering professor, Karen Chang Yan. Congratulations on their success!
Adam Novotny and Manish Paliwal
Modular designs give orthopaedic surgeons a greater flexibility to custom fit the implant to the patients bone while performing total hip arthroplasty. Titanium alloy (Ti6Al4V (ASTM F-136)) is typically used for modular hip implant stems. This highly corrosion resistant alloy forms passive surface oxide films spontaneously. However, with modular designs, micro-motion may occur at the taper junctions during mechanical loading. Crevices between the taper junctions may allow the body fluids to enter and remain stagnant. These conditions make the modular tapers susceptible to fatigue and mechanically assisted crevice corrosion. The in vivo degradation of metal alloy implants compromises the structural integrity. The influence of stress corrosion induced pits of a titanium-alloy modular implant in cement-less total hip arthroplasty was numerically investigated. The effect of pit geometry parameters — cylindrical, conical, and hemispherical dimple are compared and discussed in terms of taper performance.
Christopher Stabile and Karen Chang Yan
Electrospinning is a versatile technique to produce nano/micro fibers with controlled morphology in terms of fiber diameter, alignment etc. With multiple configurations including single axial, co-axial, tri-axial, and co-spinning, this method enables researchers to produce electrospun (ES) fibers with bioactive molecules encapsulated in order to mimic the extracellular matrix for tissue engineering applications. It is of great interest to understand and control the release rate of the bioactive molecules to examine the effects of bioactive molecules such as growth factors on cells. We developed a stochastic simulation method based on the Fick’s diffusion equation to model the diffusive behaviors of macromolecules encapsulated in electrospun fibers. This paper presents a detailed parametric study including 1) the effects of inherent random variation within the samples such as distribution of diameters, initial concentration, diffusion constants, and 2) the effects of volume of release medium. MATHEMATICA is used to carry out the simulations. The computed results are compared with experimental data in the literature.