@article{zhang_sandroni_huang_gao_oswalt_schroder_lee_shih_huang_swigart_et al._2024, title={Cardiomyocyte Alpha-1A Adrenergic Receptors Mitigate Postinfarct Remodeling and Mortality by Constraining Necroptosis}, volume={9}, ISSN={["2452-302X"]}, DOI={10.1016/j.jacbts.2023.08.013}, abstractNote={Clinical studies have shown that α1-adrenergic receptor antagonists (α-blockers) are associated with increased heart failure risk. The mechanism underlying that hazard and whether it arises from direct inhibition of cardiomyocyte α1-ARs or from systemic effects remain unclear. To address these issues, we created a mouse with cardiomyocyte-specific deletion of the α1A-AR subtype and found that it experienced 70% mortality within 7 days of myocardial infarction driven, in part, by excessive activation of necroptosis. We also found that patients taking α-blockers at our center were at increased risk of death after myocardial infarction, providing clinical correlation for our translational animal models.}, number={1}, journal={JACC-BASIC TO TRANSLATIONAL SCIENCE}, author={Zhang, Jiandong and Sandroni, Peyton B. and Huang, Wei and Gao, Xiaohua and Oswalt, Leah and Schroder, Melissa A. and Lee, Sungho and Shih, Yen -Yu I. and Huang, Hsiao-Ying S. and Swigart, Philip M. and et al.}, year={2024}, month={Jan}, pages={78–96} }
 @article{wu_pankow_onuma_huang_peters_2022, title={Comparison of High-Speed Polarization Imaging Methods for Biological Tissues}, volume={22}, ISSN={["1424-8220"]}, url={https://www.mdpi.com/1424-8220/22/20/8000}, DOI={10.3390/s22208000}, abstractNote={We applied a polarization filter array and high-speed camera to the imaging of biological tissues during large, dynamic deformations at 7000 frames per second. The results are compared to previous measurements of similar specimens using a rotating polarizer imaging system. The polarization filter eliminates motion blur and temporal bias from the reconstructed collagen fiber alignment angle and retardation images. The polarization imaging configuration dose pose additional challenges due to the need for calibration of the polarization filter array for a given sample in the same lighting conditions as during the measurement.}, number={20}, journal={SENSORS}, author={Wu, Xianyu and Pankow, Mark and Onuma, Taka and Huang, Hsiao-Ying Shadow and Peters, Kara}, year={2022}, month={Oct} }
 @article{tang_wu_klippel_zhang_huang_jing_jiang_yao_2022, title={Deep thrombosis characterization using photoacoustic imaging with intravascular light delivery}, volume={12}, ISSN={["2093-985X"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85124813833&partnerID=MN8TOARS}, DOI={10.1007/s13534-022-00216-0}, abstractNote={Venous thromboembolism (VTE) is a condition in which blood clots form within the deep veins of the leg or pelvis to cause deep vein thrombosis. The optimal treatment of VTE is determined by thrombus properties such as the age, size, and chemical composition of the blood clots. The thrombus properties can be readily evaluated by using photoacoustic computed tomography (PACT), a hybrid imaging modality that combines the rich contrast of optical imaging and deep penetration of ultrasound imaging. With inherent sensitivity to endogenous chromophores such as hemoglobin, multispectral PACT can provide composition information and oxygenation level in the clots. However, conventional PACT of clots relies on external light illumination, which provides limited penetration depth due to strong optical scattering of intervening tissue. In our study, this depth limitation is overcome by using intravascular light delivery with a thin optical fiber. To demonstrate in vitro blood clot characterization, clots with different acuteness and oxygenation levels were placed underneath ten-centimeter-thick chicken breast tissue and imaged using multiple wavelengths. Acoustic frequency analysis was performed on the received PA channel signals, and oxygenation level was estimated using multispectral linear spectral unmixing. The results show that, with intravascular light delivery, clot oxygenation level can be accurately measured, and the clot age can thus be estimated. In addition, we found that retracted and unretracted clots had different acoustic frequency spectrum. While unretracted clots had stronger high frequency components, retracted clots had much higher low frequency components due to densely packed red blood cells. The PACT characterization of the clots was consistent with the histology results and mechanical tests.}, number={2}, journal={BIOMEDICAL ENGINEERING LETTERS}, author={Tang, Yuqi and Wu, Huaiyu and Klippel, Paul and Zhang, Bohua and Huang, Hsiao-Ying Shadow and Jing, Yun and Jiang, Xiaoning and Yao, Junjie}, year={2022}, month={Feb} }
 @article{chen_kim_huang_2022, title={Exploration of the dislocation-electrochemistry relation in LiFePO4 cathode materials}, volume={237}, ISSN={["1873-2453"]}, DOI={10.1016/j.actamat.2022.118158}, abstractNote={Defects, such as dislocations, in electrode materials play a significant role in the performance of lithium-ion batteries. The dislocation-electrochemistry relation has only been observed experimentally and not been fully clarified. Computational studies on this mechanism were also very limited, especially the altered cyclic voltammetry behaviors and associated effective diffusivity. This work focuses on the influences of few characteristics of dislocations on the electrochemical performance of an anisotropic cathode material, lithium iron phosphate (LiFePO 4 ). Utilizing linear elastic mechanics and the superposition principle, we study stress and displacement fields of a LiFePO 4 particle containing different densities and orientations of dislocations. With the mechanical-electrochemical coupling effects expressed by the modified Butler-Volmer equation and using the finite different method, the cyclic voltammetry curves for different dislocation configurations in the particle are investigated. Our results show that introducing dislocations can shift and distort the cyclic voltammetry curves, especially at one specific dislocation orientation. It is also found that the Li-ion molar fraction-dependent partial molar volume is an important prerequisite of the distortion in cyclic voltammetry curves. Moreover, the altered cyclic voltammetry curves at different scanning rates indicate the improvements of electrical power, stored electrical energy, and the effective diffusivity of lithium. Our discrete dislocation model indicates that the capacity loss of LiFePO 4 nanoparticles can be alleviated by introducing tailored dislocations. This study assists the understanding of electrode materials with pre-existing dislocations and provides strategies of using defect engineering to improve the kinetic performance in lithium-ion batteries.}, journal={ACTA MATERIALIA}, author={Chen, Hongjiang and Kim, Sangwook and Huang, Hsiao-Ying Shadow}, year={2022}, month={Sep} }
 @article{chen_kim_huang_2022, title={Exploration of the dislocation-electrochemistry relation in LiFePO4 cathode materials}, volume={237}, url={https://www.sciencedirect.com/science/article/pii/S1359645422005390}, DOI={https://doi.org/10.1016/j.actamat.2022.118158}, abstractNote={Defects, such as dislocations, in electrode materials play a significant role in the performance of lithium-ion batteries. The dislocation-electrochemistry relation has only been observed experimentally and not been fully clarified. Computational studies on this mechanism were also very limited, especially the altered cyclic voltammetry behaviors and associated effective diffusivity. This work focuses on the influences of few characteristics of dislocations on the electrochemical performance of an anisotropic cathode material, lithium iron phosphate (LiFePO 4 ). Utilizing linear elastic mechanics and the superposition principle, we study stress and displacement fields of a LiFePO 4 particle containing different densities and orientations of dislocations. With the mechanical-electrochemical coupling effects expressed by the modified Butler-Volmer equation and using the finite different method, the cyclic voltammetry curves for different dislocation configurations in the particle are investigated. Our results show that introducing dislocations can shift and distort the cyclic voltammetry curves, especially at one specific dislocation orientation. It is also found that the Li-ion molar fraction-dependent partial molar volume is an important prerequisite of the distortion in cyclic voltammetry curves. Moreover, the altered cyclic voltammetry curves at different scanning rates indicate the improvements of electrical power, stored electrical energy, and the effective diffusivity of lithium. Our discrete dislocation model indicates that the capacity loss of LiFePO 4 nanoparticles can be alleviated by introducing tailored dislocations. This study assists the understanding of electrode materials with pre-existing dislocations and provides strategies of using defect engineering to improve the kinetic performance in lithium-ion batteries.}, journal={Acta Materialia}, author={Chen, Hongjiang and Kim, Sangwook and Huang, Hsiao-Ying Shadow}, year={2022}, pages={118158} }
 @article{kuznetsov_pankow_peters_huang_2020, title={A structural-based computational model of tendon-bone insertion tissues}, volume={327}, ISSN={["1879-3134"]}, DOI={10.1016/j.mbs.2020.108411}, abstractNote={Tendon-to-bone insertion provides a gradual transition from soft tendon to hard bone tissue, functioning to alleviate stress concentrations at the junction of these tissues. Such macroscopic mechanical properties are achieved due to the internal structure in which collagen fibers and mineralization levels are key ingredients. We develop a structural-based model of tendon-to-bone insertion incorporating such details as fiber preferred orientation, fiber directional dispersion, mineralization level, and their inhomogeneous spatial distribution. A python script is developed to alter the tapered tendon–bone transition zone and to provide spatial grading of material properties, which may be rather complex as experiments suggest. A simple linear interpolation between tendon and bone material properties is first used to describe the graded property within the insertion region. Stress distributions are obtained and compared for spatially graded and various piece-wise materials properties. It is observed that spatial grading results in more smooth stress distributions and significantly reduces maximum stresses. The geometry of the tissue model is optimized by minimizing the peak stress to mimic in-vivo tissue remodeling. The in-silico elastic models constructed in this work are verified and modified by comparing to our in-situ biaxial mechanical testing results, thereby serving as translational tools for accurately predicting the material behavior of the tendon-to-bone insertions. This model will be useful for understanding how tendon-to-bone insertion develops during tissue remodeling, as well as for developing orthopedic implants.}, journal={MATHEMATICAL BIOSCIENCES}, author={Kuznetsov, Sergey and Pankow, Mark and Peters, Kara and Huang, Hsiao-Ying Shadow}, year={2020}, month={Sep} }
 @article{zhang_ash_huang_smith_huang_jensen_2020, title={An Essential Protective Role for Cardiomyocyte Alpha1a-adrenergic Receptors in a Mouse Model of Myocardial Infarction}, volume={127}, ISSN={["1524-4571"]}, DOI={10.1161/res.127.suppl_1.408}, abstractNote={Our previous work reveals that dabuzalgron, an oral agonist of alpha-1A adrenergic receptors (α1A-ARs) protects rodents from pathological cardiac stress, a finding in agreement with genetic studies of global α1A-AR overexpression/inactivation. However, it remains largely obscure whether cardiomyocyte-specific actions of α1A-ARs alone determines these cardioprotective effects. To test this essential gap in knowledge, we generated a new mouse line lacking α1A-AR only on cardiomyocytes by crossing αMHC-cre mice with floxed α1A-KO mice (CMKO= cre+ fl/fl, CMWT= cre-fl/fl). After validating specific deletion, baseline features were measured by conscious echo. No overt structural or functional anomaly was identified in either group. Fractional Shortening (FS, %) was virtually identical in 2 groups (51.7±0.7 vs. 52.4±5.3, p=NS). Next, both groups were subjected to permanent left anterior descending (LAD) ligation. By day 14, CMKO had significantly higher mortality (9/15 vs 2/13, p=0.025). To determine early changes that might account for this difference, hearts were harvested at day 3 post-ligation from another cohort. HW did not differ between two groups (7.0±1.1 vs. 7.2±1.1 mg/g·BW, p=NS), neither did LW (8.0±2.1 vs. 7.2±1.0 mg/g·BW, p=NS). Serum troponin level was numerically higher in CMKO mice (8.4±12.4 vs 4.8±6.2 ng/mL,p=0.38). CMKO mice had 51% larger injury (infarcted and leukocyte-infiltrating area) compared to CMWT (31.0±10.5 vs. 20.5±4.9% of LV area, p=0.05). Our preliminary postmortem examination suggested a higher trend of cardiac rupture in injured CMKO (3/5 vs 0/5). To test myocardial biomechanical properties between 2 groups, ventricles from mice 3d post ligation were then subjected to biaxial mechanical stress test. Myocardium from infracted CMKO mice exhibited 70% more stiffness (dt Stress/dt Strain) CMWT (190±34.29 vs.111±42 kPa, p=0.004). Collectively, our results demonstrate that mice deficient of α1A-AR on cardiomyocytes had lower late survival, more profound early pathological injury & adverse mechanical properties after LAD ligation, suggesting that activation of cardiomyocyte α1A-ARs plays an essential role in protecting experimental myocadiac infarction, holds the promise of future clinical implications.}, journal={CIRCULATION RESEARCH}, author={Zhang, Jiandong and Ash, Tyler and Huang, Wei and Smith, Alan and Huang, Hsiao-Ying and Jensen, Brian C.}, year={2020}, month={Jul} }
 @article{kim_raj_li_dufek_dickerson_huang_liaw_pawar_2020, title={Correlation of electrochemical and mechanical responses: Differential analysis of rechargeable lithium metal cells}, volume={463}, ISSN={["1873-2755"]}, DOI={10.1016/j.jpowsour.2020.228180}, abstractNote={Recently, interest in high energy rechargeable lithium metal batteries has increased. Application of pressure has been identified as a distinct means to increase cycle life for these cells, but there is still a disconnect between the evolution of electrochemical and mechanical responses. For this study, lithium/NMC622 pouch cells are cycled under two different pressure conditions and pressure evolution is monitored. Applying pressure with an appropriate experimental setup not only improves performance, but also enables collection of additional information that compliments cell electrochemistry. By jointly comparing differential pressure (dP dV−1) and differential capacity (dQ dV−1) analysis, the combined electrochemical and mechanical cell responses are analyzed. It is found that while little change in cell capacity and dQ dV−1 are observed, changes in cell pressure can be used to provide in operando information on the lithium metal electrode for full pouch cells. The changes in pressure suggest it is possible to track the evolution of electrode structure from a flatter electrode early in life to a more porous negative electrode prior to the point where cell capacity begins to dramatically fade.}, journal={JOURNAL OF POWER SOURCES}, author={Kim, Sangwook and Raj, Abhi and Li, Bin and Dufek, Eric J. and Dickerson, Charles C. and Huang, Hsiao-Ying and Liaw, Boryann and Pawar, Gorakh M.}, year={2020}, month={Jul} }
 @article{kim_raj_li_dufek_dickerson_huang_liaw_pawar_2020, title={Correlation of electrochemical and mechanical responses: Differential analysis of rechargeable lithium metal cells}, volume={463}, url={https://www.sciencedirect.com/science/article/pii/S0378775320304833}, DOI={https://doi.org/10.1016/j.jpowsour.2020.228180}, abstractNote={Recently, interest in high energy rechargeable lithium metal batteries has increased. Application of pressure has been identified as a distinct means to increase cycle life for these cells, but there is still a disconnect between the evolution of electrochemical and mechanical responses. For this study, lithium/NMC622 pouch cells are cycled under two different pressure conditions and pressure evolution is monitored. Applying pressure with an appropriate experimental setup not only improves performance, but also enables collection of additional information that compliments cell electrochemistry. By jointly comparing differential pressure (dP dV−1) and differential capacity (dQ dV−1) analysis, the combined electrochemical and mechanical cell responses are analyzed. It is found that while little change in cell capacity and dQ dV−1 are observed, changes in cell pressure can be used to provide in operando information on the lithium metal electrode for full pouch cells. The changes in pressure suggest it is possible to track the evolution of electrode structure from a flatter electrode early in life to a more porous negative electrode prior to the point where cell capacity begins to dramatically fade.}, journal={Journal of Power Sources}, author={Kim, Sangwook and Raj, Abhi and Li, Bin and Dufek, Eric J. and Dickerson, Charles C. and Huang, Hsiao-Ying and Liaw, Boryann and Pawar, Gorakh M.}, year={2020}, pages={228180} }
 @article{chen_huang_2021, title={Modeling and simulation of the non-equilibrium process for a continuous solid solution system in lithium-ion batteries}, volume={212}, url={https://www.sciencedirect.com/science/article/pii/S0020768320304431}, DOI={https://doi.org/10.1016/j.ijsolstr.2020.11.014}, abstractNote={The capacity loss and cycling aging of lithium-ion batteries at high (dis)charging rate (C-rate) hinders the development of emerging technologies. To improve the performance of Li-ion batteries, it is important to understand the coupling effect of the mechanical behaviors and the electrochemical response of electrodes, as the capacity loss and cycling aging are related to the mechanics of electrodes during (dis)charging. Many studies have formulated the distribution of stress, strain and lithium-ion fraction of electrodes during lithiation/delithiation. However, few of them reported a self-consistent formulation that contains mechanical-diffusional-electrochemical coupling effects, solid viscosity, and diffusion-induced creep for an electrode with large deformation under non-equilibrium process. This paper considers the electrode of a Li-ion battery as a solid solution system. Based on continuum mechanics, non-equilibrium thermodynamics and variational theory, we develop a generalized theory to describe the variations of stress distribution, electrode material deformation and lithium-ion fractions of the solid solution system over a non-equilibrium process. The finite deformation, mass transfer, phase transformation, chemical reaction and electrical potential of the system are coupled with each other in a fully self-consistent formulation. We apply the developed theory to numerically simulate a Sn anode particle using the finite difference method. Our results compare the influences of different C-rates on the non-equilibrium process of the anode particle. Higher C-rate corresponds to stronger dissipation effects including faster plastic deformation, larger viscous stress, more polarization in the electrical potential, longer relaxation time and less electrical energy. With the formulation and simulation of the non-equilibrium process, this study refines our understanding of the mechanical-diffusional-electrochemical coupling effect in Li-ion batteries with high C-rate.}, journal={International Journal of Solids and Structures}, author={Chen, Hongjiang and Huang, Hsiao-Ying Shadow}, year={2021}, pages={124–142} }
 @article{dhiman_huang_2020, title={Dislocation based stresses during electrochemical cycling and phase transformation in lithium-ion batteries}, volume={171}, ISSN={["1879-0801"]}, DOI={10.1016/j.commatsci.2019.109275}, abstractNote={Lithium iron phosphate (LiFePO4) contains defects that play an important role in structural degradation of batteries. Linear defects called dislocations are introduced inside the lithium ion battery material during fabrication process accompanied by distortion produced stress fields around them. The present study deals with these mechanical stresses around dislocations in lithium iron phosphate and the change in stress field during phase transformation of lithium iron phosphate electrode material. A model consisting of multiple dislocations inside a lithium iron phosphate material incorporating anisotropic material properties is used to calculate stress fields using linear elastic theory and the superposition method. The stress fields around dislocations during phase transformation of lithium-iron phosphate are numerically calculated by incorporating the anisotropic properties of the material. The change in electrochemical behaviour of material due to change in stress field during phase transformation is also studied, where a modified electrochemical kinetics equation (i.e., Butler Volmer equation) is derived and used to account for dislocation induced stresses during the reversible cyclic voltammatery of the lithium iron phosphate. The results shows the stress inside material does not remain constant during phase transformation and its variations are dislocation orientation dependent. In addition, the result shows that the presence of stress fields around dislocations changes the electrochemical behaviour of the material as suggested by the shift in the cyclic voltammograms. The effect of increasing scan rate on cyclic voltammogram is also studied for lithium iron phosphate. The results show that the increase in current at peaks is independent of the orientation of dislocations studied. Moreover, the decrease in current corresponding to a particular overvoltage value before anodic peak and increase in current after the anodic peak is found to be somehow proportional to the scan rate. Increased scan rates show increased deviation of current from a cyclic voltammogram for material in which there is no phase transformation. The results provide an insight into how presence of defects and phase transformation changes the electrochemical behaviour of the material. It is concluded that the combined effect of the stresses induced around dislocations during phase transformation and high scan rate can be used for modifying battery materials for various applications by changing electrochemistry of electrodes. The present study incorporates electrochemistry, defects and phase transformation into one battery chemistry and thus is important in our understanding of the Li-ion batteries.}, journal={COMPUTATIONAL MATERIALS SCIENCE}, author={Dhiman, Pankaj and Huang, Hsiao-Ying Shadow}, year={2020}, month={Jan} }
 @article{dhiman_huang_2020, title={Dislocation based stresses during electrochemical cycling and phase transformation in lithium-ion batteries}, volume={171}, url={https://www.sciencedirect.com/science/article/pii/S0927025619305749}, DOI={https://doi.org/10.1016/j.commatsci.2019.109275}, abstractNote={Lithium iron phosphate (LiFePO4) contains defects that play an important role in structural degradation of batteries. Linear defects called dislocations are introduced inside the lithium ion battery material during fabrication process accompanied by distortion produced stress fields around them. The present study deals with these mechanical stresses around dislocations in lithium iron phosphate and the change in stress field during phase transformation of lithium iron phosphate electrode material. A model consisting of multiple dislocations inside a lithium iron phosphate material incorporating anisotropic material properties is used to calculate stress fields using linear elastic theory and the superposition method. The stress fields around dislocations during phase transformation of lithium-iron phosphate are numerically calculated by incorporating the anisotropic properties of the material. The change in electrochemical behaviour of material due to change in stress field during phase transformation is also studied, where a modified electrochemical kinetics equation (i.e., Butler Volmer equation) is derived and used to account for dislocation induced stresses during the reversible cyclic voltammatery of the lithium iron phosphate. The results shows the stress inside material does not remain constant during phase transformation and its variations are dislocation orientation dependent. In addition, the result shows that the presence of stress fields around dislocations changes the electrochemical behaviour of the material as suggested by the shift in the cyclic voltammograms. The effect of increasing scan rate on cyclic voltammogram is also studied for lithium iron phosphate. The results show that the increase in current at peaks is independent of the orientation of dislocations studied. Moreover, the decrease in current corresponding to a particular overvoltage value before anodic peak and increase in current after the anodic peak is found to be somehow proportional to the scan rate. Increased scan rates show increased deviation of current from a cyclic voltammogram for material in which there is no phase transformation. The results provide an insight into how presence of defects and phase transformation changes the electrochemical behaviour of the material. It is concluded that the combined effect of the stresses induced around dislocations during phase transformation and high scan rate can be used for modifying battery materials for various applications by changing electrochemistry of electrodes. The present study incorporates electrochemistry, defects and phase transformation into one battery chemistry and thus is important in our understanding of the Li-ion batteries.}, journal={Computational Materials Science}, author={Dhiman, Pankaj and Huang, Hsiao-Ying Shadow}, year={2020}, pages={109275} }
 @article{barbour_huang_2019, title={Strain effects on collagen proteolysis in heart valve tissues}, ISSN={1385-2000 1573-2738}, url={http://dx.doi.org/10.1007/s11043-019-09410-7}, DOI={10.1007/s11043-019-09410-7}, journal={Mechanics of Time-Dependent Materials}, publisher={Springer Nature}, author={Barbour, Kaitlyn and Huang, Hsiao-Ying Shadow}, year={2019}, month={Jan} }
 @article{benson_huang_2019, title={Tissue Level Mechanical Properties and Extracellular Matrix Investigation of the Bovine Jugular Venous Valve Tissue}, volume={6}, ISSN={2306-5354}, url={http://dx.doi.org/10.3390/bioengineering6020045}, DOI={10.3390/bioengineering6020045}, abstractNote={Jugular venous valve incompetence has no long-term remedy and symptoms of transient global amnesia and/or intracranial hypertension continue to discomfort patients. During this study, we interrogate the synergy of the collagen and elastin microstructure that compose the bi-layer extracellular matrix (ECM) of the jugular venous valve. In this study, we investigate the jugular venous valve and relate it to tissue-level mechanical properties, fibril orientation and fibril composition to improve fundamental knowledge of the jugular venous valves toward the development of bioprosthetic venous valve replacements. Steps include: (1) multi loading biaxial mechanical tests; (2) isolation of the elastin microstructure; (3) imaging of the elastin microstructure; and (4) imaging of the collagen microstructure, including an experimental analysis of crimp. Results from this study show that, during a 3:1 loading ratio (circumferential direction: 900 mN and radial direction: 300 mN), elastin may have the ability to contribute to the circumferential mechanical properties at low strains, for example, shifting the inflection point toward lower strains in comparison to other loading ratios. After isolating the elastin microstructure, light microscopy revealed that the overall elastin orients in the radial direction while forming a crosslinked mesh. Collagen fibers were found undulated, aligning in parallel with neighboring fibers and orienting in the circumferential direction with an interquartile range of −10.38° to 7.58° from the circumferential axis (n = 20). Collagen crimp wavelength and amplitude was found to be 38.46 ± 8.06 µm and 4.51 ± 1.65 µm, respectively (n = 87). Analyzing collagen crimp shows that crimp permits about 12% true strain circumferentially, while straightening of the overall fibers accounts for more. To the best of the authors’ knowledge, this is the first study of the jugular venous valve linking the composition and orientation of the ECM to its mechanical properties and this study will aid in forming a structure-based constitutive model.}, number={2}, journal={Bioengineering}, publisher={MDPI AG}, author={Benson, Adam A. and Huang, Hsiao-Ying Shadow}, year={2019}, month={May}, pages={45} }
 @article{lu_huang_2018, title={Biaxial Mechanical Behavior of Bovine Saphenous Venous Valve Leaflets}, volume={6}, ISSN={2213-333X}, url={http://dx.doi.org/10.1016/J.JVSV.2018.03.003}, DOI={10.1016/J.JVSV.2018.03.003}, abstractNote={Chronic venous disease is caused by chronic venous insufficiency (CVI), which results in significant symptoms such as venous ulcers, ankle eczema, leg swelling, etc. Venous valve incompetence is a major cause of CVI. When the valves of veins in the leg become incompetent (i.e., do not close properly), blood is able to flow backwards (i.e., reflux), which results in blood pooling in the lower extremities, distal venous hypertension, and CVI. Current clinical therapies, such as surgical venous valve reconstruction and bioprosthetic venous valve replacement, are highly invasive and only moderately successful. This is due, in part, to the scanty information available about venous valve leaflet structure and mechanical properties. To date, only one previous study by our research group has reported on the mechanical properties of venous valve leaflet tissue, and specifically in the case of jugular vein valves. In this study, we conducted equibiaxial tensile tests on bovine saphenous vein valve leaflet tissues to better understand their nonlinear, anisotropic mechanical behavior. By stretching the valvular tissues to 60% strain in both the circumferential and radial directions, we generated stress-strain curves for proximal (i.e., those closest to the heart) and distal (i.e., those furthest from the heart) valve leaflets. Histology and collagen assays were also conducted to study corresponding leaflet microstructures and the biochemical properties of the tissues. Results showed: (1) saphenous venous valve tissues possessed overall anisotropic properties. The tissues were stiffer in the circumferential direction than in the radial direction (p<0.01), and (2) saphenous venous valve tissues from the proximal end showed nonlinear isotropic mechanical properties, while those from the distal end showed nonlinear anisotropic mechanical properties. (3) Distal saphenous venous valve tissues appeared to be stiffer than proximal ones in the circumferential direction, p=0.04 (i.e., inter-valvular variability), and (4) the collagen concentration showed a decreasing trend from the proximal to the distal end. This study focuses on highly relevant animal (bovine) tissues to develop test protocols, establish biomechanical structure-function correlations, and to provide data critical to the design of clinical prosthetic venous valves. To the best of the author's knowledge, this is the first study reporting the biaxial mechanical properties of saphenous venous valve leaflet tissues and thus contributes toward refining our collective understanding of valvular tissue biomechanics.}, number={3}, journal={Journal of Vascular Surgery: Venous and Lymphatic Disorders}, publisher={Elsevier BV}, author={Lu, J. and Huang, H.S.}, year={2018}, month={May}, pages={417–418} }
 @article{kim_chen_shadow huang_2018, title={Coupled Mechanical and Electrochemical Analyses of Three-Dimensional Reconstructed LiFePO4 by Focused Ion Beam/Scanning Electron Microscopy in Lithium-Ion Batteries}, volume={16}, ISSN={2381-6872}, url={http://dx.doi.org/10.1115/1.4040760}, DOI={10.1115/1.4040760}, abstractNote={Limited lifetime and performance degradation in lithium ion batteries in electrical vehicles and power tools is still a challenging obstacle which results from various interrelated processes, especially under specific conditions such as higher discharging rates (C-rates) and longer cycles. To elucidate these problems, it is very important to analyze electrochemical degradation from a mechanical stress point of view. Specifically, the goal of this study is to investigate diffusion-induced stresses and electrochemical degradation in three-dimensional (3D) reconstructed LiFePO4. We generate a reconstructed microstructure by using a stack of focused ion beam-scanning electron microscopy (FIB/SEM) images combined with an electrolyte domain. Our previous two-dimensional (2D) finite element model is further improved to a 3D multiphysics one, which incorporates both electrochemical and mechanical analyses. From our electrochemistry model, we observe 95.6% and 88.3% capacity fade at 1.2 C and 2 C, respectively. To investigate this electrochemical degradation, we present concentration distributions and von Mises stress distributions across the cathode with respect to the depth of discharge (DoD). Moreover, electrochemical degradation factors such as total polarization and over-potential are also investigated under different C-rates. Further, higher total polarization is observed at the end of discharging, as well as at the early stage of discharging. It is also confirmed that lithium intercalation at the electrode-electrolyte interface causes higher over-potential at specific DoDs. At the region near the separator, a higher concentration gradient and over-potential are observed. We note that higher over-potential occurs on the surface of electrode, and the resulting concentration gradient and mechanical stresses are observed in the same regions. Furthermore, mechanical stress variations under different C-rates are quantified during the discharging process. With these coupled mechanical and electrochemical analyses, the results of this study may be helpful for detecting particle crack initiation.}, number={1}, journal={Journal of Electrochemical Energy Conversion and Storage}, publisher={ASME International}, author={Kim, Sangwook and Chen, Hongjiang and Shadow Huang, Hsiao-Ying}, year={2018}, month={Aug}, pages={011010} }
 @article{wu_pankow_huang_peters_2018, title={High-speed polarization imaging of dynamic collagen fiber realignment in tendon-to-bone insertion region}, volume={23}, ISSN={1083-3668}, url={http://dx.doi.org/10.1117/1.JBO.23.11.116002}, DOI={10.1117/1.JBO.23.11.116002}, abstractNote={Abstract. A high-speed polarization imaging instrument is demonstrated to be capable of measuring the collagen fiber alignment orientation and alignment strength during high-displacement rate dynamic loading at acquisition rates up to 10 kHz. The implementation of a high-speed rotating quarter wave plate and high-speed camera in the imaging system allows a minimum measurement acquisition time of 6 ms. Sliced tendon-to-bone insertion samples are loaded using a modified drop tower with an average maximum displacement rate of 1.25  m  /  s, and imaged using a high-speed polarization imaging instrument. The generated collagen fiber alignment angle and strength maps indicate the localized deformation and fiber realignment in tendon-to-bone samples during dynamic loading. The results demonstrate a viable experimental method to monitor collagen fiber realignment in biological tissue under high-displacement rate dynamic loading.}, number={11}, journal={Journal of Biomedical Optics}, publisher={SPIE-Intl Soc Optical Eng}, author={Wu, Xianyu and Pankow, Mark and Huang, Hsiao-Ying Shadow and Peters, Kara}, year={2018}, month={Nov}, pages={1} }
 @article{kim_wee_peters_huang_2018, title={Multiphysics Coupling in Lithium-Ion Batteries with Reconstructed Porous Microstructures}, volume={122}, ISSN={1932-7447 1932-7455}, url={http://dx.doi.org/10.1021/acs.jpcc.7b12388}, DOI={10.1021/acs.jpcc.7b12388}, abstractNote={For an energy storage application such as electrical vehicles (EVs), lithium-ion batteries must overcome limited lifetime and performance degradation under specific conditions. Particularly, lithiu...}, number={10}, journal={The Journal of Physical Chemistry C}, publisher={American Chemical Society (ACS)}, author={Kim, Sangwook and Wee, Junghyun and Peters, Kara and Huang, Hsiao-Ying Shadow}, year={2018}, month={Feb}, pages={5280–5290} }
 @article{kuznetsov_pankow_peters_huang_2019, title={Strain state dependent anisotropic viscoelasticity of tendon-to-bone insertion}, volume={308}, ISSN={0025-5564}, url={http://dx.doi.org/10.1016/j.mbs.2018.12.007}, DOI={10.1016/j.mbs.2018.12.007}, abstractNote={Tendon-to-bone insertion tissues may be considered as functionally-graded connective tissues, providing a gradual transition from soft tendon to hard bone tissue, and functioning to alleviate stress concentrations at the junction of these tissues. The tendon-to-bone insertion tissues demonstrate pronounced viscoelastic behavior, like many other biological tissues, and are designed by the nature to alleviate stress at physiological load rates and strains states. In this paper we present experimental data showing that under biaxial tension tendon-to-bone insertion demonstrates rate-dependent behavior and that stress-strain curves for the in-plane components of stress and strain become less steep when strain rate is increased, contrary to a typical viscoelastic behavior, where the opposite trend is observed. Such behavior may indicate the existence of a protective viscoelastic mechanism reducing stress and strain during a sudden increase in mechanical loading, known to exist in some biological tissues. The main purpose of the paper is to show that such viscoelastic stress reduction indeed possible and is thermodynamically consistent. We, therefore, propose an anisotropic viscoelasticity model for finite strain. We identify the range of parameters for this model which yield negative viscoelastic contribution into in-plane stress under biaxial state of strain and simultaneously satisfy requirements of thermodynamics. We also find optimal parameters maximizing the observed protective viscoelastic effect for this particular state of strain. This model will be useful for testing and describing viscoelastic materials and for developing interfaces for dissimilar materials, considering rate effect and multiaxial loadings.}, journal={Mathematical Biosciences}, publisher={Elsevier BV}, author={Kuznetsov, Sergey and Pankow, Mark and Peters, Kara and Huang, Hsiao-Ying Shadow}, year={2019}, month={Feb}, pages={1–7} }
 @article{lu_huang_2018, title={Biaxial mechanical behavior of bovine saphenous venous valve leaflets}, volume={77}, ISSN={1751-6161}, url={http://dx.doi.org/10.1016/j.jmbbm.2017.10.028}, DOI={10.1016/j.jmbbm.2017.10.028}, abstractNote={Chronic venous disease is caused by chronic venous insufficiency (CVI), which results in significant symptoms such as venous ulcers, ankle eczema, leg swelling, etc. Venous valve incompetence is a major cause of CVI. When the valves of veins in the leg become incompetent (i.e., do not close properly), blood is able to flow backwards (i.e., reflux), which results in blood pooling in the lower extremities, distal venous hypertension, and CVI. Current clinical therapies, such as surgical venous valve reconstruction and bioprosthetic venous valve replacement, are highly invasive and only moderately successful. This is due, in part, to the scanty information available about venous valve leaflet structure and mechanical properties. To date, only one previous study by our research group has reported on the mechanical properties of venous valve leaflet tissue, and specifically in the case of jugular vein valves. In this study, we conducted equibiaxial tensile tests on bovine saphenous vein valve leaflet tissues to better understand their nonlinear, anisotropic mechanical behavior. By stretching the valvular tissues to 60% strain in both the circumferential and radial directions, we generated stress-strain curves for proximal (i.e., those closest to the heart) and distal (i.e., those furthest from the heart) valve leaflets. Histology and collagen assays were also conducted to study corresponding leaflet microstructures and the biochemical properties of the tissues. Results showed: (1) saphenous venous valve tissues possessed overall anisotropic properties. The tissues were stiffer in the circumferential direction than in the radial direction (p<0.01), and (2) saphenous venous valve tissues from the proximal end showed nonlinear isotropic mechanical properties, while those from the distal end showed nonlinear anisotropic mechanical properties. (3) Distal saphenous venous valve tissues appeared to be stiffer than proximal ones in the circumferential direction, p=0.04 (i.e., inter-valvular variability), and (4) the collagen concentration showed a decreasing trend from the proximal to the distal end. This study focuses on highly relevant animal (bovine) tissues to develop test protocols, establish biomechanical structure-function correlations, and to provide data critical to the design of clinical prosthetic venous valves. To the best of the author's knowledge, this is the first study reporting the biaxial mechanical properties of saphenous venous valve leaflet tissues and thus contributes toward refining our collective understanding of valvular tissue biomechanics.}, journal={Journal of the Mechanical Behavior of Biomedical Materials}, publisher={Elsevier BV}, author={Lu, Jiaqi and Huang, Hsiao-Ying Shadow}, year={2018}, month={Jan}, pages={594–599} }
 @article{huang_lu_2017, title={Biaxial mechanical properties of bovine jugular venous valve leaflet tissues}, volume={16}, ISSN={1617-7959 1617-7940}, url={http://dx.doi.org/10.1007/s10237-017-0927-1}, DOI={10.1007/s10237-017-0927-1}, abstractNote={Venous valve incompetence has been implicated in diseases ranging from chronic venous insufficiency (CVI) to intracranial venous hypertension. However, while the mechanical properties of venous valve leaflet tissues are central to CVI biomechanics and mechanobiology, neither stress-strain curves nor tangent moduli have been reported. Here, equibiaxial tensile mechanical tests were conducted to assess the tangent modulus, strength and anisotropy of venous valve leaflet tissues from bovine jugular veins. Valvular tissues were stretched to 60% strain in both the circumferential and radial directions, and leaflet tissue stress-strain curves were generated for proximal and distal valves (i.e., valves closest and furthest from the right heart, respectively). Toward linking mechanical properties to leaflet microstructure and composition, Masson's trichrome and Verhoeff-Van Gieson staining and collagen assays were conducted. Results showed: (1) Proximal bovine jugular vein venous valves tended to be bicuspid (i.e., have two leaflets), while distal valves tended to be tricuspid; (2) leaflet tissues from proximal valves exhibited approximately threefold higher peak tangent moduli in the circumferential direction than in the orthogonal radial direction (i.e., proximal valve leaflet tissues were anisotropic; [Formula: see text]); (3) individual leaflets excised from the same valve apparatus appeared to exhibit different mechanical properties (i.e., intra-valve variability); and (4) leaflets from distal valves exhibited a trend of higher soluble collagen concentrations than proximal ones (i.e., inter-valve variability). To the best of the authors' knowledge, this is the first study reporting biaxial mechanical properties of venous valve leaflet tissues. These results provide a baseline for studying venous valve incompetence at the tissue level and a quantitative basis for prosthetic venous valve design.}, number={6}, journal={Biomechanics and Modeling in Mechanobiology}, publisher={Springer Nature}, author={Huang, Hsiao-Ying Shadow and Lu, Jiaqi}, year={2017}, month={Jun}, pages={1911–1923} }
 @article{chandrasekaran_pankow_peters_huang_2017, title={Composition and structure of porcine digital flexor tendon-bone insertion tissues}, volume={105}, ISSN={1549-3296}, url={http://dx.doi.org/10.1002/jbm.a.36162}, DOI={10.1002/jbm.a.36162}, abstractNote={AbstractTendon‐bone insertion is a functionally graded tissue, transitioning from 200 MPa tensile modulus at the tendon end to 20 GPa tensile modulus at the bone, across just a few hundred micrometers. In this study, we examine the porcine digital flexor tendon insertion tissue to provide a quantitative description of its collagen orientation and mineral concentration by using Fast Fourier Transform (FFT) based image analysis and mass spectrometry, respectively. Histological results revealed uniformity in global collagen orientation at all depths, indicative of mechanical anisotropy, although at mid‐depth, the highest fiber density, least amount of dispersion, and least cellular circularity were evident. Collagen orientation distribution obtained through 2D FFT of histological imaging data from fluorescent microscopy agreed with past measurements based on polarized light microscopy. Results revealed global fiber orientation across the tendon‐bone insertion to be preserved along direction of physiologic tension. Gradation in the fiber distribution orientation index across the insertion was reflective of a decrease in anisotropy from the tendon to the bone. We provided elemental maps across the fibrocartilage for its organic and inorganic constituents through time‐of‐flight secondary ion mass spectrometry (TOF‐SIMS). The apatite intensity distribution from the tendon to bone was shown to follow a linear trend, supporting past results based on Raman microprobe analysis. The merit of this study lies in the image‐based simplified approach to fiber distribution quantification and in the high spatial resolution of the compositional analysis. In conjunction with the mechanical properties of the insertion tissue, fiber, and mineral distribution results for the insertion from this may potentially be incorporated into the development of a structural constitutive approach toward computational modeling. Characterizing the properties of the native insertion tissue would provide the microstructural basis for developing biomimetic scaffolds to recreate the graded morphology of a fibrocartilaginous insertion. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 3050–3058, 2017.}, number={11}, journal={Journal of Biomedical Materials Research Part A}, publisher={Wiley}, author={Chandrasekaran, Sandhya and Pankow, Mark and Peters, Kara and Huang, Hsiao-Ying Shadow}, year={2017}, month={Aug}, pages={3050–3058} }
 @article{kaul_huang_2017, title={Constitutive modeling of jugular vein-derived venous valve leaflet tissues}, volume={75}, ISSN={1751-6161}, url={http://dx.doi.org/10.1016/j.jmbbm.2017.06.037}, DOI={10.1016/j.jmbbm.2017.06.037}, abstractNote={Venous valve tissues, though used in vein reconstruction surgeries and bioprosthetic valves with moderate success, have not been extensively studied with respect to their structure. Their inherent anisotropic, non-linear behavior combined with severe diseases which affect veins, such as chronic venous insufficiency, warrant understanding the structure and material behavior of these tissues. Hence, before any bioprosthetic grafts may be used in place of tissues, it is of the utmost importance to understand the mechanical and structural properties of these tissues as this may lead to higher success rates for valve replacement surgeries. The longevity of the bioprosthetics may also increase if the manufactured grafts behave the same as native valves. Building on the scant information about the uniaxial and biaxial mechanical properties of jugular venous valves and wall tissues from previous studies, the current focus of our investigation lies in understanding the material behavior by establishing a phenomenological strain energy-based constitutive relation for the tissues. We used bovine veins to study the behavior of valve leaflet tissue and adjoining wall tissue (from the proximal and distal ends of the veins) under different biaxial testing protocols. We looked at the behavior of numerical partial derivatives of the strain energy to select a suitable functional form for the strain energy for wall and valve tissues. Using this strain energy descriptor, we determined the Cauchy stress and compared it with experimental results under additional sets of displacement-controlled biaxial testing protocols to find material specific model parameters by the Powell's method algorithm. Results show that whereas wall tissue strain energy can be explained using a polynomial non-linear function, the valve tissue, due to higher non-linearities, requires an exponential function. This study may provide useful information for the primary stages of bioprosthetic designs and replacement surgeries and may support future studies investigating structural models. It may also support the study of valvular diseases by providing a way to understand material properties and behavior and to form a continuum model when required for numerical analyses and computational simulations.}, journal={Journal of the Mechanical Behavior of Biomedical Materials}, publisher={Elsevier BV}, author={Kaul, Nayyan and Huang, Hsiao-Ying Shadow}, year={2017}, month={Nov}, pages={50–57} }
 @article{wu_pankow_shadow huang_peters_2017, title={High-speed polarized light microscopy for in situ, dynamic measurement of birefringence properties}, volume={29}, ISSN={0957-0233 1361-6501}, url={http://dx.doi.org/10.1088/1361-6501/aa9084}, DOI={10.1088/1361-6501/aa9084}, abstractNote={A high-speed, quantitative polarized light microscopy (QPLM) instrument has been developed to monitor the optical slow axis spatial realignment during controlled medium to high strain rate experiments at acquisition rates up to 10 kHz. This high-speed QPLM instrument is implemented within a modified drop tower and demonstrated using polycarbonate specimens. By utilizing a rotating quarter wave plate and a high-speed camera, the minimum acquisition time to generate an alignment map of a birefringent specimen is 6.1 ms. A sequential analysis method allows the QPLM instrument to generate QPLM data at the high-speed camera imaging frequency 10 kHz. The obtained QPLM data is processed using a vector correlation technique to detect anomalous optical axis realignment and retardation changes throughout the loading event. The detected anomalous optical axis realignment is shown to be associated with crack initiation, propagation, and specimen failure in a dynamically loaded polycarbonate specimen. The work provides a foundation for detecting damage in biological tissues through local collagen fiber realignment and fracture during dynamic loading.}, number={1}, journal={Measurement Science and Technology}, publisher={IOP Publishing}, author={Wu, Xianyu and Pankow, Mark and Shadow Huang, Hsiao-Ying and Peters, Kara}, year={2017}, month={Dec}, pages={015203} }
 @article{ayers_huang_2016, title={A comprehensive finite element model for lithium–oxygen batteries}, volume={31}, ISSN={0884-2914 2044-5326}, url={http://dx.doi.org/10.1557/jmr.2016.306}, DOI={10.1557/jmr.2016.306}, abstractNote={Abstract}, number={18}, journal={Journal of Materials Research}, publisher={Cambridge University Press (CUP)}, author={Ayers, Martin W. and Huang, Hsiao-Ying Shadow}, year={2016}, month={Sep}, pages={2728–2735} }
 @article{wu_huang_pankow_peters_2017, title={Dynamic Polarization Microscopy for In-Situ Measurements of Collagen Fiber Realignment During Impact}, ISBN={["978-3-319-41350-1"]}, ISSN={["2191-5652"]}, DOI={10.1007/978-3-319-41351-8_9}, abstractNote={The long term goal of this work is to better understand the tendon-to-bone insertion injury due to medium strain rate impact (e.g. sports activity). Specifically, we imaged collagen fiber realignment during impact, to investigate the ability of the tendon-to-bone insertion to these survive harsh dynamic events. A polarized light microscopy (PLM) setup was built in the lab and used to monitor the birefringence property changes of a known material under changing stress conditions. Initially polycarbonate dogbone specimens were tested quasi-statically to validate the setup and analysis algorithm. Polarized light retardation and alignment direction images are generated to quantitatively analyze the birefringence property change under different stress and compared to theoretical predictions. To perform dynamic experiments a drop weight tower was modified for medium strain rate testing (10–100 %/s) and the PLM setup is being incorporated for imaging. Several dynamic experiments have been conducted using this modified drop tower on porcine tendon specimens. A high-speed camera is used to record their dynamic response and deformation.}, journal={MECHANICS OF BIOLOGICAL SYSTEMS AND MATERIALS, VOL 6}, author={Wu, Xianyu and Huang, Hsiao-Ying Shadow and Pankow, Mark and Peters, Kara}, year={2017}, pages={61–66} }
 @article{kim_huang_2016, title={Mechanical stresses at the cathode–electrolyte interface in lithium-ion batteries}, volume={31}, ISSN={0884-2914 2044-5326}, url={http://dx.doi.org/10.1557/jmr.2016.373}, DOI={10.1557/jmr.2016.373}, abstractNote={Abstract}, number={22}, journal={Journal of Materials Research}, publisher={Cambridge University Press (CUP)}, author={Kim, Sangwook and Huang, Hsiao-Ying Shadow}, year={2016}, month={Oct}, pages={3506–3512} }
 @article{stamps_eischen_huang_2016, title={Particle- and crack-size dependency of lithium-ion battery materials LiFePO₄}, volume={3}, ISSN={2372-0484}, url={http://dx.doi.org/10.3934/matersci.2016.1.190}, DOI={10.3934/matersci.2016.1.190}, abstractNote={Lithium-ion batteries have become a widely-used commodity for satisfying the world’s mobile power needs. However, the mechanical degradation of lithium-ion batteries initiated by micro cracks is considered to be a bottleneck for advancing the current technology. This study utilizes a finite element method-based virtual crack closure technique to obtain particle- and crack-size-dependent estimates of mixed-mode energy release rates and stress intensity factors. Interfacial cracks in orthotropic bi-materials are considered in the current study, whereas the crack extension along the interface is assumed. The results show that energy release rate, stress intensity factor, and the propensity of crack extension are particle- and crack-size- dependent. In particular, our results show that for smaller plate-like LiFePO 4 particles (100 nm × 45 nm), a crack has lesser tendency to extend if crack-to-particle size is less than 0.2, and for 200 nm × 90 nm particles, similar results are obtained for crack-to-particle sizes of less than 0.15. However, for larger particles (500 nm × 225 nm), it requires an almost flawless particle to have no crack extension. Therefore, the current study provides insight into the fracture mechanics of LiFePO 4 and the associated crack-to-particle size dependency to prevent crack extensions.}, number={1}, journal={AIMS Materials Science}, publisher={American Institute of Mathematical Sciences (AIMS)}, author={Stamps, Michael A. and Eischen, Jeffrey W. and Huang, Hsiao-Ying Shadow}, year={2016}, pages={190–203} }
 @article{huang_huang_2015, title={Biaxial stress relaxation of semilunar heart valve leaflets during simulated collagen catabolism: Effects of collagenase concentration and equibiaxial strain state}, volume={229}, ISSN={0954-4119 2041-3033}, url={http://dx.doi.org/10.1177/0954411915604336}, DOI={10.1177/0954411915604336}, abstractNote={ Heart valve leaflet collagen turnover and remodeling are innate to physiological homeostasis; valvular interstitial cells routinely catabolize damaged collagen and affect repair. Moreover, evidence indicates that leaflets can adapt to altered physiological (e.g. pregnancy) and pathological (e.g. hypertension) mechanical load states, tuning collagen structure and composition to changes in pressure and flow. However, while valvular interstitial cell-secreted matrix metalloproteinases are considered the primary effectors of collagen catabolism, the mechanisms by which damaged collagen fibers are selectively degraded remain unclear. Growing evidence suggests that the collagen fiber strain state plays a key role, with the strain-dependent configuration of the collagen molecules either masking or presenting proteolytic sites, thereby protecting or accelerating collagen proteolysis. In this study, the effects of equibiaxial strain state on collagen catabolism were investigated in porcine aortic valve and pulmonary valve tissues. Bacterial collagenase (0.2 and 0.5 mg/mL) was utilized to simulate endogenous matrix metalloproteinases, and biaxial stress relaxation and biochemical collagen concentration served as functional and compositional measures of collagen catabolism, respectively. At a collagenase concentration of 0.5 mg/mL, increasing the equibiaxial strain imposed during stress relaxation (0%, 37.5%, and 50%) yielded significantly lower median collagen concentrations in the aortic valve ( p = 0.0231) and pulmonary valve ( p = 0.0183), suggesting that relatively large strain magnitudes may enhance collagen catabolism. Collagen concentration decreases were paralleled by trends of accelerated normalized stress relaxation rate with equibiaxial strain in aortic valve tissues. Collectively, these in vitro results indicate that biaxial strain state is capable of affecting the susceptibility of valvular collagens to catabolism, providing a basis for further investigation of how such phenomena may manifest at different strain magnitudes or in vivo. }, number={10}, journal={Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine}, publisher={SAGE Publications}, author={Huang, Siyao and Huang, Hsiao-Ying Shadow}, year={2015}, month={Sep}, pages={721–731} }
 @inproceedings{danley_huang_2015, title={Biomechanical and biochemical study of muscle-tendon-bone in porcine digital flexor tendon}, DOI={10.1115/imece2015-52360}, abstractNote={The musculoskeletal system provides the body with both movement and support. In particular, contractile forces developed in the muscles are transmitted through the muscle-tendon junction (MTJ) into the tendon and then through the tendon-bone insertion into the bone. Each junction occurs between two dissimilar materials (muscle-to-tendon and tendon-to-bone) and neither is fully understood. The current study analyzes the relationship between the tissue microstructure and macro-scale biomechanical properties of the muscle-tendon-bone unit to better understand the anisotropic mechanical behavior of the tissue. Collagen content was assayed at various locations along the porcine digital flexor tendon. Collagen concentration as a percent of the wet weight in the bone end was found to be 20.4±5.2% (n=6), the mid tendon to be 20.6±5.3% (n=6), and the muscle end to be 25.2±3.6% (n=4). No statistical differences were found between these collagen concentrations.
               Additionally, to the best of the authors’ knowledge, this is the first study to report cross-sectional stress-strain data for the muscle-tendon-bone unit. Results indicate that the tendon cross-sectional stiffness increases from the proximal end to the distal end. However, no direction dependent anisotropies were found between the mediolateral and dorsopalmar directions. Effects of microstructural components, such as glycosaminoglycans and collagen, and phenomenon such as fibril sliding and cross-linking, are discussed in relation to the reported cross-section stress-strain response. This work provides a synergistic approach for quantifying biomechanical and biochemical properties of biological tissue, and potentially facilitates the development of tissue engineered MTJ and tendon-bone insertion.}, booktitle={ASME International Mechanical Engineering Congress and Exposition (IMECE)}, author={Danley, B. and Huang, H. S.}, year={2015} }
 @article{chiuhuang_huang_2015, title={Critical lithiation for C-rate dependent mechanical stresses in LiFePO4}, volume={19}, ISSN={1432-8488 1433-0768}, url={http://dx.doi.org/10.1007/s10008-015-2836-5}, DOI={10.1007/s10008-015-2836-5}, number={8}, journal={Journal of Solid State Electrochemistry}, publisher={Springer Science and Business Media LLC}, author={ChiuHuang, Cheng-Kai and Huang, Hsiao-Ying Shadow}, year={2015}, month={Apr}, pages={2245–2253} }
 @inproceedings{huang_huang_gettys_prim_harrysson_2014, title={A biomechanical study of directional mechanical properties of porcine skin tissues}, booktitle={Proceedings of the ASME International Mechanical Engineering Congress and Exposition, 2013, vol 9}, author={Huang, H. Y. S. and Huang, S. Y. and Gettys, T. and Prim, P. M. and Harrysson, O. L.}, year={2014} }
 @article{huang_huang_frazier_prim_harrysson_2014, title={Directional Biomechanical Properties Of Porcine Skin Tissue}, volume={14}, ISSN={0219-5194 1793-6810}, url={http://dx.doi.org/10.1142/S0219519414500699}, DOI={10.1142/S0219519414500699}, abstractNote={ Skin is a multilayered composite material and composed principally of the proteins collagen, elastic fibers and fibroblasts. The direction-dependent material properties of skin tissue is important for physiological functions like skin expansion. The current study has developed methods to characterize the directional biomechanical properties of porcine skin tissues as studies have shown that pigs represent a useful animal model due to similarities between porcine and human skin. It is observed that skin tissue has a nonlinear anisotropy biomechanical behavior, where the parameters of material modulus is 378 ± 160 kPa in the preferred-fiber direction and 65.96 ± 40.49 kPa in the cross-fiber direction when stretching above 30% strain equibiaxially. The result from the study provides methods of characterizing biaxial mechanical properties of skin tissue, as the collagen fiber direction appears to be one of the primary determinants of tissue anisotropy. }, number={05}, journal={Journal of Mechanics in Medicine and Biology}, publisher={World Scientific Pub Co Pte Lt}, author={Huang, Hsiao Ying Shadow and Huang, Siyao and Frazier, Colin P. and Prim, Peter M. and Harrysson, Ola}, year={2014}, month={Aug}, pages={1450069} }
 @article{huang_huang_frazier_prim_harrysson_2014, title={Directional biomechanical properties of porcine skin tissue}, volume={14}, number={5}, journal={Journal of Mechanics in Medicine and Biology}, author={Huang, H. Y. S. and Huang, S. Y. and Frazier, C. P. and Prim, P. M. and Harrysson, O.}, year={2014} }
 @inproceedings{chiuhuang_zhou_huang_2014, title={Exploring lithium-ion intensity and distribution via a time-of-flight secondary ion mass spectroscopy}, booktitle={Proceedings of the ASME International Mechanical Engineering Congress and Exposition, 2013, vol 10}, author={ChiuHuang, C. K. and Zhou, C. Z. and Huang, H. Y. S.}, year={2014} }
 @article{chiuhuang_zhou_shadow huang_2014, title={In Situ Imaging of Lithium-Ion Batteries Via the Secondary Ion Mass Spectrometry}, volume={5}, ISSN={1949-2944}, url={http://dx.doi.org/10.1115/1.4028010}, DOI={10.1115/1.4028010}, abstractNote={To develop lithium-ion batteries with a high rate-capability and low cost, the prevention of capacity loss is one of major challenges, which needs to be tackled in the lithium-ion battery industry. During electrochemical processes, lithium ions diffuse from and insert into battery electrodes accompanied with the phase transformation, whereas ionic diffusivity and concentration are keys to the resultant battery capacity. In the current study, we compare voltage versus capacity of lithium-ion batteries at different current-rates (C-rates) discharging. Larger hysteresis and voltage fluctuations are observed in higher C-rate samples. We investigate origins of voltage fluctuations by quantifying lithium-ion intensity and distribution via a time-of-flight secondary ion mass spectrometry (ToF-SIMS). The result shows that for fully discharged samples, lithium-ion intensity and distribution are not C-rate dependent, suggesting different lithium-ion insertion mechanisms at a higher C-rate discharging might be solely responsible for the observed low frequency voltage fluctuation.}, number={2}, journal={Journal of Nanotechnology in Engineering and Medicine}, publisher={ASME International}, author={ChiuHuang, Cheng-Kai and Zhou, Chuanzhen and Shadow Huang, Hsiao-Ying}, year={2014}, month={Aug}, pages={021002} }
 @article{chiuhuang_zhou_huang_2014, title={In-situ imaging of lithium-ion batteries via the secondary ion mass spectrometry}, volume={5}, number={2}, journal={Journal of Nanotechnology in Engineering and Medicine}, author={ChiuHuang, C.-K. and Zhou, C. and Huang, H.-Y. S.}, year={2014} }
 @article{huang_huang_2014, title={Prediction of matrix-to-cell stress transfer in heart valve tissues}, volume={41}, ISSN={0092-0606 1573-0689}, url={http://dx.doi.org/10.1007/s10867-014-9362-z}, DOI={10.1007/s10867-014-9362-z}, abstractNote={Non-linear and anisotropic heart valve leaflet tissue mechanics manifest principally from the stratification, orientation, and inhomogeneity of their collagenous microstructures. Disturbance of the native collagen fiber network has clear consequences for valve and leaflet tissue mechanics and presumably, by virtue of their intimate embedment, on the valvular interstitial cell stress–strain state and concomitant phenotype. In the current study, a set of virtual biaxial stretch experiments were conducted on porcine pulmonary valve leaflet tissue photomicrographs via an image-based finite element approach. Stress distribution evolution during diastolic valve closure was predicted at both the tissue and cellular levels. Orthotropic material properties consistent with distinct stages of diastolic loading were applied. Virtual experiments predicted tissue- and cellular-level stress fields, providing insight into how matrix-to-cell stress transfer may be influenced by the inhomogeneous collagen fiber architecture, tissue anisotropic material properties, and the cellular distribution within the leaflet tissue. To the best of the authors' knowledge, this is the first study reporting on the evolution of stress fields at both the tissue and cellular levels in valvular tissue and thus contributes toward refining our collective understanding of valvular tissue micromechanics while providing a computational tool enabling the further study of valvular cell–matrix interactions.}, number={1}, journal={Journal of Biological Physics}, publisher={Springer Science and Business Media LLC}, author={Huang, Siyao and Huang, Hsiao-Ying Shadow}, year={2014}, month={Oct}, pages={9–22} }
 @article{huang_subramanian_2014, title={Special Section on Spectroscopy, Scattering, and Imaging Techniques for Nanostructured Materials}, volume={5}, ISSN={1949-2944}, url={http://dx.doi.org/10.1115/1.4028352}, DOI={10.1115/1.4028352}, abstractNote={Nanotechnology has seen rapid progress in recent years, with the emergence of advanced capabilities to synthesize and characterize precisely engineered materials that point toward disruptive new performance regimes of relevance for diverse application areas. Understanding how the atomic, electronic, mechanical, and magnetic structures/properties of materials relate to their performance across multiple length-scales is, thus, of growing importance. This special topic titled “Spectroscopy, Scattering, and Imaging Techniques for Nanostructured Materials” focuses on understanding these fundamental processes, which occur within material systems in the atomic or nanoscopic regime, using advanced tools such as time-of-flight secondary ion mass spectrometry, scanning electron microscopy (SEM), X-ray diffraction (XRD), helium ion microscopy (HIM), atomic force microscopy, Raman thermometry, and in situ imaging techniques. This understanding is being leveraged by the scientific community to deliver new knowledge that has the potential to improve the performance of different material systems: lithium-ion battery materials, biological materials, nanostructured materials for energy applications, carbon nanofiber, nanoparticles, nanowires (NW), silicon microcantilevers, etc. The special topic brings together a wide variety of excellent contributions from the scientific community showcasing the depth and breadth in this vibrant topical area within nanotechnology. The collection of papers exemplifies how the current state-of-the-art of imaging and spectroscopic techniques provides new insights into these exciting nano and biological materials with unprecedented resolution. Seven papers were submitted to this special section. Chiu Huang and colleagues at North Carolina State University investigate the origins of voltage fluctuations in high discharging current rate (C-rate) lithium-ion batteries by quantifying lithium-ion intensity and distribution via time-of-flight secondary ion mass spectrometry. Interestingly, it is observed that lithium-ion intensity and distribution are not C-rate dependent, suggesting that different lithium-ion insertion mechanisms might be solely responsible for the observed low-frequency voltage fluctuation at higher C-rates. The paper from Palapati et al. at Virginia Commonwealth University investigates elastic modulus measurements on large diameter NW using a nano-assembled platform. The nanomechanical platform is constructed by assembling single NWs across pairs of gold nano-electrodes using dielectrophoresis and contains a short, suspended segment of the NW (in air) between the assembly electrodes. AFM force spectroscopy measurements are followed. The study demonstrates the measurement technique using lithium iron phosphate NW, which is a cathodic material of interest for battery applications, as a model system and presents a finite element model to extract the Young’s modulus from nanomechanical data. This data is relevant for use within computational models that predict the stresses and cycle-life capabilities of battery nanomaterial systems. Samykano et al. at the North Carolina A&T State University provide morphological and crystallographic characterization of nickel NW synthesized by template based electrodeposition method. The structure and morphology of the synthesized NW are studied using HIM and SEM methods. The crystallographic properties of the grown NW are also studied using XRD. The results clearly indicate that properties of synthesized nickel NW are strongly influenced by the applied magnetic field and current density intensity during the synthesis process. Zhang and colleagues at Purdue University have utilized Raman thermometry to characterize bone materials and studied the influence of structural hierarchy on physical properties such as thermal conductivity and its correlation with mechanical stresses. The unique analytic-experimental approach provides stressthermal conductivity correlation in bovine cortical bone as a function of nanomechanical compressive stress and temperature changes. It is observed that the thermal conductivity values increase and then decrease as a function of increase in compressive strain in bone tissues. Goudarzi et al. at University of British Columbia characterize different lignin powders via XRD and study the variations in the XRD patterns during carbon nanofiber formation. The results indicate that the graphite peak for (101) plane is available in the grinded carbon nanofibers, and it is suggested that the available sulfate groups in lignins might facilitate graphite formation in carbon nanofiber production process. Tomar’s research group at Purdue University reports in situ creep properties of silicon microcantilevers in the temperature range of 25 C to 100 C under uni-axial compressive stress; as the silicon structures are commonly subject to this temperature range and the stress level of tens to hundreds of MPa in micro-electromechanical systems. The results reveal that in the stress range of 50–150 MPa, the strain rate of the silicon cantilever increases linearly as a function of applied stress, and the strain rate also increases as a function of increased temperature. Moreover, the sensitivity of the strain rate change with respect to change in temperature or stress is much lower comparing with the literature values. It is suggested the nearsurface atoms of the microscale silicon exhibit a relaxed state signified by lower surface stress values than bulk, especially at high temperature. Jingjie Zhang and Da-Ren Chen at Virginia Commonwealth University have provided a review article on differential mobility particle sizers for nanoparticle characterization. These instruments are used for characterizing gas-borne particles in submicrometer and nanometer diameter ranges. Specifically, aerosol chargers, differential mobility analyzers (DMA), and particle concentration detectors are discussed. This article gives an interesting overview of the state-of-art DMAs, which are particularly designed for sizing particles with the sizes down to sub-10 nm.}, number={2}, journal={Journal of Nanotechnology in Engineering and Medicine}, publisher={ASME International}, author={Huang, Hsiao-Ying Shadow and Subramanian, Arunkumar}, year={2014}, month={Sep}, pages={020201} }
 @article{huang_subramanian_2014, title={Spectroscopy, scattering and imaging techniques for nanostructured materials}, volume={5}, number={2}, journal={Journal of Nanotechnology in Engineering and Medicine}, author={Huang, H.-Y. S. and Subramanian, A.}, year={2014} }
 @inproceedings{huang_huang_2014, title={Tissue- and cell-level stress distributions of the heart valve tissue during diastole}, booktitle={Proceedings of the ASME International Mechanical Engineering Congress and Exposition, 2013, vol 9}, author={Huang, S. Y. and Huang, H. Y. S.}, year={2014} }
 @inproceedings{huang_huang_gettys_prim_harrysson_2013, place={San Diego, CA}, title={A Biomechanical Study of Directional Mechanical Properties of Porcine Skin Tissues}, DOI={10.1115/IMECE2013-63829}, abstractNote={Skin is a multilayered composite material and composed principally of the proteins collagen, elastic fibers, and fibroblasts. The direction-dependent material properties of skin tissue is important for physiological functions like skin expansion. The current study has developed methods to characterize the directional biomechanical properties of porcine skin tissues. It is observed that skin tissue has a nonlinear anisotropy biomechanical behavior, where the parameters of material stiffness is 378 ±160 kPa in the preferred-fiber direction and 65.96±40.49 kPa in the cross-fiber direction when stretching above 30% strain equibiaxially. The results from the current study will help optimize functional skin stretching for patients requiring large surface area skin grafts and reconstructions due to burns or other injuries.}, booktitle={Proceedings of the ASME International Mechanical Engineering Congress and Exposition}, author={Huang, Hsiao-Ying Shadow and Huang, Siyao and Gettys, Taylor and Prim, Peter and Harrysson, Ola}, year={2013} }
 @inproceedings{huang_huang_gettys_harrysson_2013, title={A biomechanical study of directional mechanical properties of porcine skin tissues}, booktitle={ASME 2013 International Mechanical Engineering Congress & Exposition}, author={Huang, H.-Y. S. and Huang, S. and Gettys, T. A. and Harrysson, O.}, year={2013} }
 @inproceedings{chiuhuang_zhou_huang_2013, place={San Diego, CA}, title={Exploring lithium-ion intensity and distribution via a Time-of-Flight Secondary Ion Mass Spectroscopy}, volume={IMECE2013-63013}, DOI={10.1115/imece2013-63013}, abstractNote={For high rate-capability and low cost lithium-ion batteries, the prevention of capacity loss is one of major challenges facing by lithium-ion batteries today. During electrochemical processes, lithium ions diffuse from and insert into battery electrodes accompanied with the phase transformation, where ionic diffusivity and concentration are keys to the resultant battery capacity. In the current study, we first compare voltage vs. capacity curves at different C-rates (1C, 2C, 6C, 10C). Second, lithium-ion distributions and intensity are quantified via the Time-of-Flight Secondary Ion Mass Spectroscopy (ToF-SIMS). The result shows that voltage vs. capacity relations are C-rate dependent and larger hystereses are observed in the higher C-rate samples. Detailed quantification of lithium-ion intensity for the 1C sample is conducted. It is observed that lithium-ions are distributed uniformly inside the electrode. Therefore, the current study provides a qualitative and quantitative data to better understand C-rate dependent phenomenon of LiFePO4 battery cells.}, booktitle={ASME International Mechanical Engineering Congress and Exposition Proceeding}, author={ChiuHuang, Cheng-Kai and Zhou, Chuanzhen and Huang, Hsiao-Ying Shadow}, year={2013} }
 @inproceedings{chiuhuang_stamps_huang_2013, place={San Francisco, CA}, title={Mechanics of Diffusion-Induced Fractures in Lithium-ion Battery Materials}, volume={1541}, booktitle={Materials Research Soaciety 2013 Spring Meeting}, author={ChiuHuang, Cheng-Kai and Stamps, Michael A. and Huang, Hsiao-Ying Shadow}, year={2013}, pages={1541–F04-04} }
 @article{chiuhuang_shadow huang_2013, title={Stress Evolution on the Phase Boundary in LiFePO4Particles}, volume={160}, ISSN={0013-4651 1945-7111}, url={http://dx.doi.org/10.1149/2.079311jes}, DOI={10.1149/2.079311jes}, abstractNote={It is commonly thought that diffusion-induced stress is one of the main factors causing loss of capacity in electrode materials. To understand stress evolution on the phase boundary during the lithiation process, we develop a finite element model adopting lithium ion concentration-dependent anisotropic material properties and volume misfits. Increased mechanical stresses on the phase boundaries are observed during the lithiation process. When the particle is more fully lithiated, larger stresses occur on the free surfaces and these may be related to the cracks on the ac-plane. The C-rate dependent strain energy evolution is also studied. The result shows that with the same amount of lithiation, particles experience different strain energies due to varied C-rate discharging. The high elastic energy from the high C-rate model suggests that the system becomes unstable, and a homogeneous phase transformation path is more plausible for the system. The current study provides a connection between diffusion-induces stresses on the phase boundary and the cracking propensity on free surfaces. Thus, the study could be used to better understand the mechanisms that cause particle fracture and capacity loss. © 2013 The Electrochemical Society. [DOI: 10.1149/2.079311jes] All rights reserved.}, number={11}, journal={Journal of The Electrochemical Society}, publisher={The Electrochemical Society}, author={ChiuHuang, Cheng-Kai and Shadow Huang, Hsiao-Ying}, year={2013}, pages={A2184–A2188} }
 @inproceedings{huang_huang_2013, place={San Diego, CA}, title={Tissue- and cell-levels stress distribution of heart valve tissue during diastole}, DOI={10.1115/imece2013-63229}, abstractNote={Heart valves are inhomogeneous microstructure with nonlinear anisotropic properties and constantly experience different stress states during cardiac cycles. However, how tissue-level mechanical forces can translate into altered cellular stress states remains unclear, and associated biomechanical regulation in the tissue has not been fully understood. In the current study, we use an image-based finite element method to investigate factors contributing the stress distributions at both tissue- and cell-levels inside the healthy heart valve tissues. Effects of tissue microstructure, inhomogeneity, and anisotropic material property at different diastole states are discussed to provide a better understanding of structure-mechanics-property interactions, which alters tissue-to-cell stress transfer mechanisms in heart valve tissue. To the best of the authors’ knowledge, this is the first study reporting on the evolution of stress fields at both the tissue- and cellular-levels in valvular tissue, and thus contributes toward refining our collective understanding of valvular tissue micromechanics while providing a computational tool enabling further study of valvular cell-tissue interactions.}, booktitle={Proceedings of the ASME International Mechanical Engineering Congress and Exposition}, author={Huang, Siyao and Huang, Hsiao-Ying Shadow}, year={2013} }
 @article{huang_huang_2013, title={Virtualisation of stress distribution in heart valve tissue}, volume={17}, ISSN={1025-5842 1476-8259}, url={http://dx.doi.org/10.1080/10255842.2013.763937}, DOI={10.1080/10255842.2013.763937}, abstractNote={This study presents an image-based finite element analysis incorporating histological photomicrographs of heart valve tissues. We report stress fields inside heart valve tissues, where heterogeneously distributed collagen fibres are responsible for transmitting forces into cells. Linear isotropic and anisotropic tissue material property models are incorporated to quantify the overall stress distributions in heart valve tissues. By establishing an effective predictive method with new computational tools and by performing virtual experiments on the heart valve tissue photomicrographs, we clarify how stresses are transferred from matrix to cell. The results clearly reveal the roles of heterogeneously distributed collagen fibres in mitigating stress developments inside heart valve tissues. Moreover, most local peak stresses occur around cell nuclei, suggesting that higher stress may be mediated by cells for biomechanical regulations.}, number={15}, journal={Computer Methods in Biomechanics and Biomedical Engineering}, publisher={Informa UK Limited}, author={Huang, Siyao and Huang, Hsiao-Ying Shadow}, year={2013}, month={Mar}, pages={1696–1704} }
 @inproceedings{huang_balhouse_huang_2012, place={Houston TX}, title={A Biomechanical and Biochemical Synergy Study of Heart Valve Tissue}, DOI={10.1115/imece2012-87997}, abstractNote={The function of heart valves is to allow blood to flow through the heart smoothly and to prevent retrograde flow of blood. Previous studies have shown that the mechanical properties of heart valve tissues, microstructures of extracellular matrix, and collagen concentrations are the keys to the healthy heart valves and, therefore, are crucial to the development of viable tissue-engineered heart valve replacements. Therefore, this study investigates the relationship between these factors in native porcine aortic and pulmonary valves and provides insights to the healthy heart valves. Heart valve leaflets are prepared for biaxial stretching to obtain mechanical properties. The average collagen concentrations of heart valve leaflets are determined via an assay kit. The results indicate that aortic valves are stiffer than pulmonary valves macroscopically and stiffness varies more in the circumferential direction for the aortic valve than it does for the pulmonary valve. Microscopically, it is due to collagen fibers in aortic valves are more in alignment than ones in pulmonary valves, which are more randomly in direction. Collagen assay results show that collagen concentrations are higher in the edges of pulmonary valves than in aortic valves. The results also suggest the duration of extraction may have significant affects on the concentration results. This work provides quantified stress and strain environment within heart valve tissues to help further studies on how to treat heart valve disease and create more viable heart valve replacements.}, booktitle={Proceedings of the ASME International Mechanical Engineering Congress and Exposition}, author={Huang, Hsiao-Ying Shadow and Balhouse, Brittany N. and Huang, Siyao}, year={2012}, pages={235–240} }
 @inproceedings{chiuhuang_huang_2012, place={Houston, Texas}, title={A Diffusion Model in a Two-Phase Interfacial Zone for Nanoscale Lithium-ion Battery Materials}, DOI={10.1115/imece2012-89235}, abstractNote={The development of lithium-ion batteries plays an important role to stimulate electric vehicle (EV) and plug-in electric vehicle (PHEV) industries and it is one of many solutions to reduce US oil import dependence. To develop advanced vehicle technologies that use energy more efficiently, retaining the lithium-ion battery capacity is one of major challenges facing by the electrochemical community today. During electrochemical processes, lithium ions diffuse from and insert into nanoscaled cathode materials in which stresses are formed. It is considered that diffusion-induced stress is one of the factors causing electrode material capacity loss and failure. In this study, we present a model which is capable for describing diffusion mechanisms and stress formation in nano-platelike cathode materials, LiFePO4 (Lithium-iron-phosphate). We consider particle size >100 nm in this study since it has been suggested that very small nanoparticles (<100 nm) may not undergo phase separation during fast diffusion. To evaluate diffusion-induced stress accurately, factors such as the diffusivity and phase boundary movements are considered. Our result provides quantitative lithium concentrations inside LiFePO4 nanoparticles. The result could be used for evaluating stress formation and provides potential cues for precursors of capacity loss in lithium-ion batteries. This study contributes to the fundamental understanding of lithium ion diffusion in electrode materials, and results from this model help better electrode materials design in lithium-ion batteries.}, booktitle={Proceedings of the ASME International Mechanical Engineering Congress and Exposition}, author={ChiuHuang, Cheng-Kai and Huang, Hsiao-Ying Shadow}, year={2012}, pages={1231–1237} }
 @inproceedings{huang_wang_2012, title={An overview of lithium-ion battery cathode materials}, volume={1363-RR05-30}, booktitle={Materials Research Society Symposium Proceedings}, author={Huang, H.-Y. S. and Wang, Y.-X. R.}, year={2012} }
 @article{huang_balhouse_huang_2012, title={Application of simple biomechanical and biochemical tests to heart valve leaflets: Implications for heart valve characterization and tissue engineering}, volume={226}, ISSN={0954-4119 2041-3033}, url={http://dx.doi.org/10.1177/0954411912455004}, DOI={10.1177/0954411912455004}, abstractNote={ A simple biomechanical test with real-time displacement and strain mapping is reported, which provides displacement vectors and principal strain directions during the mechanical characterization of heart valve tissues. The maps reported in the current study allow us to quickly identify the approximate strain imposed on a location in the samples. The biomechanical results show that the aortic valves exhibit stronger anisotropic mechanical behavior than that of the pulmonary valves before 18% strain equibiaxial stretching. In contrast, the pulmonary valves exhibit stronger anisotropic mechanical behavior than aortic valves beyond 28% strain equibiaxial stretching. Simple biochemical tests are also conducted. Collagens are extracted at different time points (24, 48, 72, and 120 h) at different locations in the samples. The results show that extraction time plays an important role in determining collagen concentration, in which a minimum of 72 h of extraction is required to obtain saturated collagen concentration. This work provides an easy approach for quantifying biomechanical and biochemical properties of semilunar heart valve tissues, and potentially facilitates the development of tissue engineered heart valves. }, number={11}, journal={Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine}, publisher={SAGE Publications}, author={Huang, Hsiao-Ying S and Balhouse, Brittany N and Huang, Siyao}, year={2012}, month={Aug}, pages={868–876} }
 @inproceedings{wang_huang_2012, title={Comparison of lithium-ion battery cathode materials and the internal stress development}, booktitle={Proceedings of the ASME International Mechanical Engineering Congress and Exposition, 2011, vol 4, pts A and B}, author={Wang, Y. X. and Huang, H. Y. S.}, year={2012}, pages={1685–1694} }
 @article{shadow huang_wang_2012, title={Dislocation Based Stress Developments in Lithium-Ion Batteries}, volume={159}, ISSN={0013-4651 1945-7111}, url={http://dx.doi.org/10.1149/2.090206jes}, DOI={10.1149/2.090206jes}, abstractNote={It has been suggested that structural failures are the primary factor responsible for the observed rate-capacity fade of lithium-ion batteries. In the present study, we report three different lithium intercalation-induced dislocation mechanisms explaining experimentally observed cracks. We use the theory of elasticity and the superposition method to investigate stress and force fields between multiple dislocations. In most cases, dislocations are not perfectly parallel to one specific axis. Therefore, stress variations for arbitrary Burger’s vectors are investigated. The stress fields manifesting between dislocations are numerically calculated and anisotropic material properties of electrodes are employed. The result shows that multiple dislocations are likely to be orthogonal to each other to reduce the total energy. In addition, studies have shown that when the discharging rate is increased, the capacity decreases due to the buildup of the internal elastic/plastic energy. Therefore, the stress fields of dislocation interactions in our study could be used to deduce and suggest the most feasible modes of crack formation and to provide insights into the lost of capacity in LiFePO4. Thus, the current study provide links between stress fields and the observed structural failure in lithium-ion batteries. © 2012 The Electrochemical Society. [DOI: 10.1149/2.090206jes] All rights reserved.}, number={6}, journal={Journal of The Electrochemical Society}, publisher={The Electrochemical Society}, author={Shadow Huang, Hsiao-Ying and Wang, Yi-Xu}, year={2012}, pages={A815–A821} }
 @article{wang_huang_2012, title={Lithium-Ion Battery Materials and Mechanical Stress Fields}, volume={1}, number={5}, journal={TSEST Transaction on Control and Mechanical Systems}, author={Wang, Yixu and Huang, Hsiao-Ying Shadow}, year={2012}, pages={192–200} }
 @inproceedings{stamps_huang_2012, place={Houston, TX}, title={Mixed Modes Fracture and Fatigue Evaluation for Lithium-ion Batteries}, DOI={10.1115/imece2012-88037}, abstractNote={Lithium ion batteries have become a widely known commodity for satisfying the world’s mobile energy storage needs. But these needs are becoming increasingly important, especially in the transportation industry, as concern for rising oil prices and environmental impact from fossil fuels are pushing for deployment of more electric vehicles (EV) or plug in hybrid-electric vehicles (PHEV) and renewable energy sources. The objective of this research is to obtain a fundamental understanding of degradation mechanisms and rate-capacity loss in lithium-ion batteries through fracture mechanics and fatigue analysis approaches. In this study we follow empirical observations that mechanical stresses accumulate on electrode materials during the cycling process. Crack induced fracturing will then follow in the material which electrical contact surface area is degraded and over capacitance of the battery reduces. A fatigue analysis simulation is applied using ANSYS finite element software coupled with analytical models to alleviate these parameters that play the most pivotal roles in affecting the rate-capacity and cycle life of the lithium-ion battery. Our results have potential to provide new models and simulation tools for clarifying the interplay of structure mechanics and electrochemistry while offering an increased understanding of fatigue degradation mechanisms in rechargeable battery materials. These models can aid manufacturers in the optimization of battery materials to ensure longer electrochemical cycling life with high-rate capacity for improved consumer electronics, electric vehicles, and many other military or space applications.}, booktitle={Proceedings of the ASME International Mechanical Engineering Congress and Exposition}, author={Stamps, Michael A. and Huang, Hsiao-Ying Shadow}, year={2012}, pages={97–103} }
 @article{huang_huang_2012, title={Real-Time Strain Mapping via Biaxial Stretching in Heart Valve Tissues}, DOI={10.1109/EMBC.2012.6347520}, abstractNote={Previous studies show that the collagen fiber architecture is key to the heart valves tissue mechanical property. We report a real-time strain mapping approach that provides displacement vectors and principal strain directions during the mechanical characterization of heart valve tissues. The strain maps reported in the current study allows an individual to quickly identify the approximate strain imposed on a location of the sample. The result shows that when samples are biaxially stretched under 18% strain, less anisotropy is observed in both aortic and pulmonary valve leaflet samples. Moreover, when samples are stretched from 28% to 35%, pulmonary valves leaflet samples exhibits a stronger anisotropic effect than aortic valve. Therefore, a higher degree of straightening is required for collagen fibers to be fully aligned. This work provides an easy approach to quantify mechanical properties with the corresponding strain maps of heart valve tissues and potentially facilitates the developments of tissue engineering heart valves.}, journal={2012 Annual International Conference of the Ieee Engineering in Medicine and Biology Society (Embc)}, author={Huang, Hsiao-Ying Shadow and Huang, Siyao}, year={2012}, pages={6653–6656} }
 @inproceedings{huang_huang_2012, title={Real-time strain mapping via biaxial stretching in heart valve tissues}, booktitle={IEEE Engineering in Medicine and Biology Society Conference Proceedings}, author={Huang, H.-Y. S. and Huang, S.}, year={2012}, pages={324–349} }
 @article{huang_huang_2012, title={Virtual Experiments of Heart Valve Tissues}, DOI={10.1109/EMBC.2012.6347518}, abstractNote={The heart valve tissue mainly contains collagen fibers and valve interstitial cells (VICs) and constantly experiences different stress states during cardiac cycles. Due to the anisotropic architecture of collagen fibers and highly inhomogeneous cell population, the mechanical behavior of the heart valve becomes more complicated. It is known that external mechanical stimuli can lead to extracellular matrix (ECM) remodeling, cellular mechanotransduction, cell migration, and collagen synthesis; however, the mechanism of matrix-to-cell stress transfer remains unclear. Current study presents heterogeneously distributed collagen fibers responsible for transmitting forces into cells by an image-based finite element analysis incorporating histological photomicrographs of porcine heart valve tissues. Besides, nonlinear and anisotropic material properties tissue models are incorporated to quantify and visualize the overall stress distributions in heart valve tissues. By establishing an effectively predictive method with new computational tools and by performing virtual experiments on the heart valves, the role of load transmission in heart valves is clarified. The current study completely illustrates the stress distribution around cells and demonstrates the force transmission and reception between cells and matrix in the heart valve tissue. Therefore, our developed image-based finite element models provide new insights not only into clarifying the role of the force transmission and reception between heterogeneously distributed collagen fibers, but also a better understanding of relationships between the mechanical stimuli, cellular mechanotransduction, cell migration, matrix synthesis, and tissue remodeling in heart valves.}, journal={2012 Annual International Conference of the Ieee Engineering in Medicine and Biology Society (Embc)}, author={Huang, Siyao and Huang, Hsiao-Ying S.}, year={2012}, pages={6645–6648} }
 @inproceedings{huang_huang_2012, title={Virtual experiments of heart valve tissues}, booktitle={IEEE Engineering in Medicine and Biology Society Conference Proceedings}, author={Huang, S. and Huang, H.-Y. S.}, year={2012}, pages={324–349} }
 @inproceedings{wang_huang_2011, place={San Francisco, CA}, title={An Overview of Lithium-Ion Battery Cathode Materials}, DOI={10.1557/opl.2011.1363}, abstractNote={ABSTRACTThe need for the development and deployment of reliable and efficient energy storage devices, such as lithium-ion rechargeable batteries, is becoming increasingly important due to the scarcity of petroleum. In this work, we provide an overview of commercially available cathode materials for Li-ion rechargeable batteries and focus on characteristics that give rise to optimal energy storage systems for future transportation modes. The study shows that the development of lithium-iron-phosphate (LiFePO4) batteries promises an alternative to conventional lithiumion batteries, with their potential for high energy capacity and power density, improved safety, and reduced cost. This work contributes to the fundamental knowledge of lithium-ion battery cathode materials and helps with the design of better rechargeable batteries, and thus leads to economic and environmental benefits.}, booktitle={Materials Research Society 2011 Spring Meeting}, author={Wang, Yi-Xu and Huang, Hsiao-Ying Shadow}, year={2011}, pages={1363–RR05-30} }
 @inproceedings{wang_huang_2011, place={Denver, CO}, title={Comparison of Lithium-ion battery cathode materials and the internal stress development}, DOI={10.1115/IMECE2011-65663}, abstractNote={The need for development and deployment of reliable and efficient energy storage devices, such as lithium-ion rechargeable batteries, is becoming increasingly important due to the scarcity of petroleum. Lithium-ion batteries operate via an electrochemical process in which lithium ions are shuttled between cathode and anode while electrons flowing through an external wire to form an electrical circuit. The study showed that the development of lithium-iron-phosphate (LiFePO4) batteries promises an alternative to conventional lithium-ion batteries, with their potential for high energy capacity and power density, improved safety, and reduced cost. However, current prototype LiFePO4 batteries have been reported to lose capacity over ∼3000 charge/discharge cycles or degrade rapidly under high discharging rate. In this study, we report that the mechanical and structural failures are attributed to dislocations formations. Analytical models and crystal visualizations provide details to further understand the stress development due to lithium movements during charging or discharging. This study contributes to the fundamental understanding of the mechanisms of capacity loss in lithium-ion battery materials and helps the design of better rechargeable batteries, and thus leads to economic and environmental benefits.}, booktitle={Proceedings of the ASME International Mechanical Engineering Congress and Exposition}, author={Wang, Yi-Xu and Huang, Hsiao-Ying Shadow}, year={2011}, pages={1685–1694} }
 @article{tang_huang_meethong_kao_carter_chiang_2009, title={Model for the Particle Size, Overpotential, and Strain Dependence of Phase Transition Pathways in Storage Electrodes: Application to Nanoscale Olivines}, volume={21}, ISSN={0897-4756 1520-5002}, url={http://dx.doi.org/10.1021/cm803172s}, DOI={10.1021/cm803172s}, abstractNote={In the drive toward improved electrical energy storage for applications ranging from wireless devices to electric vehicles to grid stabilization, nanoscale materials are of growing interest as ion storage electrodes. Nanoscale olivines based on LiMPO4 (M = Fe, Mn, Co, Ni) are one class of compounds for which recent experimental developments reveal very different phase transition and solid-solubility behavior compared to larger particles. The olivines may be an exemplar for generalized behavior for which metastable crystalline or amorphous phases are produced under the large driving forces incurred during electrochemical reactions. Here we use a diffuse-interface thermodynamic model to assess the conditions under which amorphous phase transitions may occur in nanoscale LiMPO4 particles. There are three central conclusions. First, assuming as with similar solids that the amorphous phase has the lower surface energy, it is found that an initially crystalline phase may undergo amorphization during cycling whe...}, number={8}, journal={Chemistry of Materials}, publisher={American Chemical Society (ACS)}, author={Tang, M. and Huang, H.-Y. and Meethong, N. and Kao, Y.-H. and Carter, W. C. and Chiang, Y.-M.}, year={2009}, month={Apr}, pages={1557–1571} }
 @article{tang_huang_meethong_kao_carter_chiang_2009, title={Modeling the overpotential, particle size and strain dependence of phase transition pathways in battery electrodes: Example in nanoscale olivines}, volume={21}, journal={Chemistry of Materials}, author={Tang, M. and Huang, H.-Y. S. and Meethong, N. and Kao, Y.-H. and Carter, W. C. and Chiang, Y.-M.}, year={2009}, pages={1557–1571} }
 @article{meethong_kao_tang_huang_carter_chiang_2008, title={Electrochemically Induced Phase Transformation in Nanoscale Olivines Li1−xMPO4(M = Fe, Mn)}, volume={20}, ISSN={0897-4756 1520-5002}, url={http://dx.doi.org/10.1021/cm801722f}, DOI={10.1021/cm801722f}, abstractNote={The phase stability and phase transformation kinetics of Li1−xMPO4 olivines are critical to their performance as lithium storage electrodes. In this work, nanoscale (<100 nm primary particle size) Li1−xFePO4 and Li1−xMnPO4 are chosen as model systems for comparison with a coarser-grained LiFePO4 that exhibits a conventional two-phase reaction. The nanoscale materials first exhibit time and state-of-charge dependences of the electrochemical potential and structural parameters which show that stable two-phase coexistence is not reached. The evolution of structural parameters supports the existence of a coherency stress influenced crystal−crystal transformation. However, an additional response, the preferential formation of amorphous phase at nanosize scale, is identified. In Li1−xFePO4, at 34 nm average particle size, at least one amorphous phase of varying Li content coexists with the crystalline phases. In Li1−xMnPO4 of 78 nm particle size, the electrochemically formed delithiated phase is highly disorder...}, number={19}, journal={Chemistry of Materials}, publisher={American Chemical Society (ACS)}, author={Meethong, Nonglak and Kao, Yu-Hua and Tang, Ming and Huang, Hsiao-Ying and Carter, W. Craig and Chiang, Yet-Ming}, year={2008}, month={Oct}, pages={6189–6198} }
 @article{meethong_kao_tang_huang_carter_chiang_2008, title={Electrochemically induced phase transformation in nanoscale olivines Li(1-x)MPO4 (M=Fe, Mn)}, volume={20}, journal={Chemistry of Materials}, author={Meethong, N. and Kao, Y.-H. and Tang, M. and Huang, H.-Y. S. and Carter, W. C. and Chiang, Y.-M.}, year={2008}, pages={6189–6198} }
 @inproceedings{tang_huang_meethong_kao_carter_chiang_2008, title={Modeling particle size effects on phase stability and transition pathways in nanosized plivine cathode particles}, volume={1100}, booktitle={Materials Research Society Symposium Proceedings}, author={Tang, M. and Huang, H.-Y. S. and Meethong, N. and Kao, Y.-H. and Carter, W. C. and Chiang, Y.-M.}, year={2008}, pages={JJ03–04} }
 @article{huang_liao_sacks_2007, title={In-Situ Deformation of the Aortic Valve Interstitial Cell Nucleus Under Diastolic Loading}, volume={129}, ISSN={0148-0731}, url={http://dx.doi.org/10.1115/1.2801670}, DOI={10.1115/1.2801670}, abstractNote={Within the aortic valve (AV) leaflet resides a population of interstitial cells (AVICs), which serve to maintain tissue structural integrity via protein synthesis and enzymatic degradation. AVICs are typically characterized as myofibroblasts, exhibit phenotypic plasticity, and may play an important role in valve pathophysiology. While it is known that AVICs can respond to mechanical stimuli in vitro, the level of in vivo AVIC deformation and its relation to local collagen fiber reorientation during the cardiac cycle remain unknown. In the present study, the deformation of AVICs was investigated using porcine AV glutaraldehyde fixed under 0–90mmHg transvalvular pressures. The resulting change in nuclear aspect ratio (NAR) was used as an index of overall cellular strain, and dependencies on spatial location and pressure loading levels quantified. Local collagen fiber alignment in the same valves was also quantified using small angle light scattering. A tissue-level finite element (FE) model of an AVIC embedded in the AV extracellular matrix was also used explore the relation between AV tissue- and cellular-level deformations. Results indicated large, consistent increases in AVIC NAR with transvalvular pressure (e.g., from mean of 1.8 at 0mmHg to a mean of 4.8 at 90mmHg), as well as pronounced layer specific dependencies. Associated changes in collagen fiber alignment indicated that little AVIC deformation occurs with the large amount of fiber straightening for pressures below ∼1mmHg, followed by substantial increases in AVIC NAR from 4mmHgto90mmHg. While the tissue-level FE model was able to capture the qualitative response, it also underpredicted the extent of AVIC deformation. This result suggested that additional micromechanical and fiber-compaction effects occur at high pressure levels. The results of this study form the basis of understanding transvalvular pressure-mediated mechanotransduction within the native AV and first time quantitative data correlating AVIC nuclei deformation with AV tissue microstructure and deformation.}, number={6}, journal={Journal of Biomechanical Engineering}, publisher={ASME International}, author={Huang, Hsiao-Ying Shadow and Liao, Jun and Sacks, Michael S.}, year={2007}, month={Apr}, pages={880} }
 @article{huang_2007, title={In-situ deformation of the aortic heart valve interstitial cell nucleus under diastolic-loading}, volume={129}, journal={Journal of Biomechanical Engineering}, author={Huang, H.-Y. S.}, year={2007}, pages={880–889} }
 @article{meethong_huang_carter_chiang_2007, title={Size-Dependent Lithium Miscibility Gap in Nanoscale Li[sub 1−x]FePO[sub 4]}, volume={10}, ISSN={1099-0062}, url={http://dx.doi.org/10.1149/1.2710960}, DOI={10.1149/1.2710960}, abstractNote={Olivine compounds have emerged as important and enabling positive electrode materials for high-power, safe, long-life lithium rechargeable batteries. In this work, the miscibility gap in undoped Li 1-x FePO 4 is shown to contract systematically with decreasing particle size in the nanoscale regime and with increasing temperature at a constant particle size. These effects suggest that the miscibility gap completely disappears below a critical size. In the size-dependent regime, the kinetic response of nanoscale olivines should deviate from the simple size-scaling implicit in Fickian diffusion.}, number={5}, journal={Electrochemical and Solid-State Letters}, publisher={The Electrochemical Society}, author={Meethong, Nonglak and Huang, Hsiao-Ying Shadow and Carter, W. Craig and Chiang, Yet-Ming}, year={2007}, pages={A134} }
 @article{meethong_huang_carter_chiang_2007, title={Size-dependent lithium miscibility gap in nanoscale Li(1-x)FePO4}, volume={10}, number={5}, journal={Electrochemical and Solid State Letters}, author={Meethong, N. and Huang, H.-Y. S. and Carter, W. C. and Chiang, Y.-M.}, year={2007}, pages={A134–138} }
 @article{meethong_huang_speakman_carter_chiang_2007, title={Strain Accommodation during Phase Transformations in Olivine-Based Cathodes as a Materials Selection Criterion for High-Power Rechargeable Batteries}, volume={17}, ISSN={1616-301X}, url={http://dx.doi.org/10.1002/adfm.200600938}, DOI={10.1002/adfm.200600938}, abstractNote={AbstractHigh energy lithium‐ion batteries have improved performance in a wide variety of mobile electronic devices. A new goal in portable power is the achievement of safe and durable high‐power batteries for applications such as power tools and electric vehicles. Towards this end, olivine‐based positive electrodes are amongst the most important and technologically enabling materials. While certain lithium metal phosphate olivines have been shown to be promising, not all olivines demonstrate beneficial properties. The mechanisms allowing high power in these compounds have been extensively debated. Here we show that certain high rate capability olivines are distinguished by having extended lithium nonstoichiometry (up to ca. 20 %), with which is correlated a reduced lattice misfit as the material undergoes an electrochemically driven, reversible, first‐order phase transformation. The rate capability in several other intercalation oxides can also be correlated with lattice strain, and suggests that nanomechanics plays an important and previously unrecognized role in determining battery performance.}, number={7}, journal={Advanced Functional Materials}, publisher={Wiley}, author={Meethong, N. and Huang, H.-Y. S. and Speakman, S. A. and Carter, W. C. and Chiang, Y.-M.}, year={2007}, month={Mar}, pages={1115–1123} }
 @article{meethong_huang_speakman_carter_chiang_2007, title={Strain Accommodation during Phase Transformations in Olivine-Based Cathodes as a Materials Selection Criterion for High-Power Rechargeable Batteries}, volume={17}, url={https://onlinelibrary.wiley.com/doi/abs/10.1002/adfm.200600938}, DOI={https://doi.org/10.1002/adfm.200600938}, abstractNote={AbstractHigh energy lithium‐ion batteries have improved performance in a wide variety of mobile electronic devices. A new goal in portable power is the achievement of safe and durable high‐power batteries for applications such as power tools and electric vehicles. Towards this end, olivine‐based positive electrodes are amongst the most important and technologically enabling materials. While certain lithium metal phosphate olivines have been shown to be promising, not all olivines demonstrate beneficial properties. The mechanisms allowing high power in these compounds have been extensively debated. Here we show that certain high rate capability olivines are distinguished by having extended lithium nonstoichiometry (up to ca. 20 %), with which is correlated a reduced lattice misfit as the material undergoes an electrochemically driven, reversible, first‐order phase transformation. The rate capability in several other intercalation oxides can also be correlated with lattice strain, and suggests that nanomechanics plays an important and previously unrecognized role in determining battery performance.}, number={7}, journal={Advanced Functional Materials}, author={Meethong, N. and Huang, H.-Y. S. and Speakman, S. A. and Carter, W. C. and Chiang, Y.-M.}, year={2007}, pages={1115–1123} }
 @inproceedings{huang_sacks_2006, title={Geometric changes in heart valve interstitial cell nuclei with transvalvular pressure}, booktitle={5th World Congress of Biomechanics, Munich, Germany, July 29-August 4, 2006}, author={Huang, H.-Y. S. and Sacks, M. S.}, year={2006}, pages={5640} }
 @article{david merryman_shadow huang_schoen_sacks_2006, title={The effects of cellular contraction on aortic valve leaflet flexural stiffness}, volume={39}, ISSN={0021-9290}, url={http://dx.doi.org/10.1016/j.jbiomech.2004.11.008}, DOI={10.1016/j.jbiomech.2004.11.008}, abstractNote={The aortic valve (AV) leaflet contains a heterogeneous interstitial cell population composed predominantly of myofibroblasts, which contain both fibroblast and smooth muscle cell characteristics. The focus of the present study was to examine aortic valve interstitial cell (AVIC) contractile behavior within the intact leaflet tissue. Circumferential strips of porcine AV leaflets were mechanically tested under flexure, with the AVIC maintained in the normal, contracted, and contraction-inhibited states. Leaflets were flexed both with (WC) and against (AC) the natural leaflet curvature, both before and after the addition of 90 mM KCl to elicit cellular contraction. In addition, a natural basal tonus was also demonstrated by treating the leaflets with 10 microM thapsigargin to completely inhibit AVIC contraction. Results revealed a 48% increase in leaflet stiffness with AVIC contraction (from 703 to 1040 kPa, respectively) when bent in the AC direction (p=0.004), while the WC direction resulted only in 5% increase (from 491 to 516.5 kPa, respectively--not significant) in leaflet stiffness in the active state. Also, the loss of basal tonus of the AVIC population with thapsigargin treatment resulted in 76% (AC, p=0.001) and 54% (WC, p=0.036) decreases in leaflet stiffness at 5 mM KCl levels, while preventing contraction with the addition of 90 mM KCl as expected. We speculate that the observed layer dependent effects of AVIC contraction are primarily due to varying ECM mechanical properties in the ventricularis and fibrosa layers. Moreover, while we have demonstrated that AVIC contractile ability is a significant contributor to AV leaflet bending stiffness, it most likely serves a role in maintaining AV leaflet tissue homeostasis that has yet to be elucidated.}, number={1}, journal={Journal of Biomechanics}, publisher={Elsevier BV}, author={David Merryman, W. and Shadow Huang, Hsiao-Ying and Schoen, Frederick J. and Sacks, Michael S.}, year={2006}, month={Jan}, pages={88–96} }
 @inproceedings{tollner_huang_2004, title={A shaft design aid for integrating basic elements of introductory machine design}, booktitle={American Society for Engineering Education Annual Conference & Exposition, Salt Lake City, Utah}, author={Tollner, E. W. and Huang, H.-Y. S.}, year={2004}, pages={66} }
 @inproceedings{sun_huang_argento_sacks_2003, place={Cambridge, MA}, title={Finite Element Implementation of a Structural Constitutive Model for Planar Collagenous Tissues}, ISBN={0080440487}, booktitle={Proceedings of the Second MIT Conference on Computational Solid and Fluid Mechanics}, publisher={Amsterdam: Elsevier Science,}, author={Sun, W. and Huang, Hsiao-Ying Shadow and Argento, M.S. and Sacks, M. S.}, year={2003}, pages={210} }
 @article{huang_huang, title={Biaxial Stress Relaxation of Semilunar Heart Valve Leaflets during Simulated Collagen Catabolism: Effects of Collagenase Concentration and Equibiaxial Strain-State}, journal={Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine}, author={Huang, Siyao and Huang, Hsiao-Ying Shadow} }
 @article{chiuhuang_huang, title={Critical Lithiation for C-rate Dependent Mechanical Stresses in LiFePO4}, journal={Journal of Solid State Electrochemistry}, author={ChiuHuang, C. K. and Huang, Hsiao-Ying Shadow} }
 @article{stamps_eischen_huang, title={Particle- and Crack-Size Dependency of Lithium-ion Battery Materials LiFePO4}, journal={Journal of Engineering Mechanics}, author={Stamps, Michael A. and Eischen, Jeffrey W. and Huang, Hsiao-Ying Shadow} }