Biological Materials Science: Biological Materials Science IV
Sponsored by: TMS Functional Materials Division, TMS Structural Materials Division, TMS: Biomaterials Committee
Program Organizers: David Restrepo, University of Texas at San Antonio; Steven Naleway, University of Utah; Jing Du, Pennsylvania State University; Ning Zhang, Baylor University
Thursday 2:00 PM
March 18, 2021
Room: RM 12
Location: TMS2021 Virtual
Session Chair: Steven Naleway, The University of Utah; Ning Zhang, The University of Alabama
2:00 PM Invited
Understanding Heterogeneity in Bone Adaptation Following Exercise: Mariana Kersh1; Sony Manandhar1; Hyunggwi Song1; John Polk1; 1University of Illinois at Urbana-Champaign
While exercise is accepted as a means for improving bone strength, the relationship between strain-states and degree of bone adaptation has not been well quantified. We evaluated femoral bone in young sheep using 2 modes of exercise: 60 days of flat vs. inclined walking. Bone volume fraction (BV/TV) increased in tensile zones while density decreased did not change. The largest increases in density occurred in regions of compression within the inclined exercise group; with negligible increases in BV/TV. These results suggest adaptation to compression occurs via changes in material composition while adaptation to tension results in increased bone area. Our analyses of trabecular bone near the joint surface, which is primarily in compression, support this hypothesis: density increased by 5% following exercise but there was no change in thickness. However, thickness increased in the middle condylar zone which may have trabeculae that experience both tensile and compressive loads.
2:30 PM
Internal Strain Mapping for Native and Implanted Glenoids: Yuxiao Zhou1; Gregory Lewis1; April Armstrong1; Jing Du1; 1Penn State University
The most common cause for the failure total shoulder replacement surgeries is loosening of the glenoid component implant. Mechanical factors are widely reported to be crucial in glenoid component loosening. In this study, mechanical testing coupled with micro X-ray computed tomography (micro-CT) is carried out on a human cadaveric glenoid specimen. Several physiologically realistic loading conditions were applied on the native and implanted specimen. Digital volume correlation is used to compute the 3D full-field strain inside the glenoid. The measured strain distributions are in good agreement with the results of analytical models, especially for the two eccentric loadings conditions. The overall effective moduli of the native and implanted glenoid were similar. However, under the same anteriorly/posteriorly eccentric loading conditions, a wider range of strain appeared inside the implanted glenoid. The increased strain range can be attributed to the glenoid component placement, which increased the bending moment inside the glenoid.
2:50 PM
Negative Compressibility Architected Materials for Novel Cardiac Patches: Juan Sebastian Rincon Tabares1; David Restrepo1; Juan Velasquez1; Hai-Chao Han1; 1University of Texas at San Antonio
Myocardial infarction (MI) produces a deterioration of the pump function, leading to heart failure. Currently, Cardiac patches (CPs) are used to strengthen the infarcted wall to improve cardiac function post-MI. However, CPs have two major limitations: (i) CPs can only provide passive support to the scar tissue and no ability to assist heart contraction. (ii) CPs need to be stiff enough to provide sufficient support but cannot be too stiff to limit diastolic filling. It is of clinical interest to design new materials to fulfill these limitations. In this work, we present a new architected material that generates localized shrinkage (contraction) when subject to tension from surrounding heart wall tissue contraction, so it can assist heart contraction (enhance systolic function) and conform better to the natural heart movements and mechanical properties. Specifically, we will discuss the design, mechanical features, and limitations of such material.
3:10 PM
Investigating the Effect of Morphological Parameters on the Sound-Induced Mechanical Response of Mosquito Antennae: Adwait Trikanad1; Hoover Pantoja-Sánchez1; Ximena Bernal2; Pablo Zavattieri1; 1Purdue University; 2Purdue University, Smithsonian Tropical Research Institute
Mosquitos lack tympanal ears to detect sound. Instead they use light-weighted sensory structures, their plumose antennae, which are deflected by sound induced air vibrations. While most mosquitos rely on their antennae for sound detection in the acoustic near field, the antenna of frog-biting mosquitoes, Uranotaenia lowii, is unusual in its ability to detect far-field acoustic cues. Females of this species are attracted to the distant mating calls of male frogs. This study investigates the role of the different morphological parameters in the antennal system of Ur. lowii and their effect on the mechanical response. The study aims to identify the governing structural parameters responsible for its ability to detect far-field acoustic cues through a comparative analysis with a widely studied mosquito species – Aedes aegypti. Results could be potentially useful in developing mechanical systems sensitive to low intensity vibrations in a high noise environment.