Nos efforts se sont portés sur des fluorophosphates de structure TAVORITE de formule LiMPO4F (M = V, Fe, Ti) et LiVPO4O qui, comparés à d’autres familles structurales de phosphates tels que Li3M2(PO4)3 (NASICON) ou LiFePO4(OH) (Tavorite) possèdent d’excellentes densités d’énergie théorique comme matériaux d’électrodes dans des accumulateurs au Li. Des méthodes de synthèse reproductibles, par voie céramique en tubes scellés et/ou ionothermale (synthèse à basse température), ont été mises au point dans ce travail. Les matériaux ainsi préparés ont été caractérisés en détail par magnétométrie, par RMN et surtout par diffraction des rayons X et des neutrons. Les structures cristallines ont ainsi pu être déterminées ainsi que les mécanismes d’insertion/extraction du Li+, via de nombreuses études par diffraction X insitu lors de la charge/décharge des accumulateurs. / This work focused on TAVORITE-based fluorophosphates LiMPO4F (M = V, Fe, Ti) and LiVPO4O which, when compared with other phosphate structural families such as Li3V2(PO4)3 (NASICON) or LiFePO4(OH) (Tavorite), possess superior energy density as electrode materials for Li batteries. Reproducible synthesis procedures were developed through “classical” ceramic routes in sealed containers and/or low temperature ionothermal reaction. The obtained materials were characterized by magnetometry, solid state NMR and heavily by X-Ray and Neutron diffraction. The crystal structures of all the materials were determined, as well as the mechanisms of Li+ insertion/extraction through insitu X-Ray diffraction during electrochemical charge/discharge of the batteries.

O espalhamento eletromagnético por uma esfera com propriedades ópticas e raio arbitrários, conhecido como espalhamento de Lorenz-Mie, ou por um cilindro circular infinito, pode ser resolvido analiticamente e é comumente tratado dentro da abordagem de espalhadores dielétricos. Na região óptica, tanto meio circundante quanto partícula espalhadora possuem o mesmo valor de permeabilidade magnética. A ausência do magnetismo nessa região do espectro torna o índice de refração relativo entre os meios interno e externo ao espalhador homogêneo equivalente ao respectivo índice de impedância óptica. Em regiões espectrais de micro-ondas ou radiofrequências, entretanto, materiais ferro- e ferrimagnéticos podem exibir valores absolutos de permeabilidade magnética extremamente elevados, reduzindo então a impedância óptica em comparação ao valor correspondente de índice de refração relativo. Uma característica marcante vinculada ao magnetismo no centro espalhador é que pequenas partículas comparadas com o comprimento de onda (parâmetros de tamanho na região de Rayleigh) podem apresentar grandes seções de choque de extinção a despeito de suas pequenas seções de choque geométricas. Isso torna possível, fisicamente, a presença de picos de ressonância morfológica na energia eletromagnética interna ao centro espalhador mesmo na região de parâmetros de tamanho inferiores à unidade. Em especial, mostramos que essa energia eletromagnética possui, no regime de fraca absorção, uma relação funcional simples com o comprimento de onda incidente e a seção de choque de absorção da partícula espalhadora, independentemente do formato geométrico da mesma. No espalhamento por uma coleção de partículas magnéticas, a velocidade de transporte de energia pode ser estimada a partir da energia eletromagnética média que é armazenada no interior de um centro espalhador isolado. Dessa maneira, a validade da relação universal que encontramos entre o fator de aumento da energia eletromagnética interna ao centro espalhador e sua correspondente seção de choque de absorção (no regime de baixa absorção óptica) implica na possibilidade de estimarmos de maneira simples a velocidade de transporte de energia em um meio desordenado. Um resultado decorrente dessa aproximação é que mesmo na região de Rayleigh a velocidade de transporte de energia em um meio magnético desordenado é drasticamente reduzida, levando, por conseguinte, à redução do coeficiente de difusividade dos fótons no meio. O estudo analítico e numérico da energia eletromagnética armazenada por uma esfera e por um cilindro magnéticos irradiados por ondas planas homogêneas são os temas em foco nesta dissertação de Mestrado. / Electromagnetic scattering by a sphere with arbitrary optical properties and radius, known as the Lorenz-Mie scattering, or by an infinite right circular cylinder can be solved analytically and is widely treated in the approach of dielectric scatterers. In the optical range, both embedding medium and scattering particle have the same magnetic permeability. The absence of magnetism in this spectral range leads to the equivalence between the relative refraction and impedance indices associated with the scatterers. However, in microwave or radio-frequency ranges, ferro- and ferrimagnetic materials can exhibit extremely huge values of magnetic permeability, which reduce the optical impedance in comparison to the corresponding value of relative refraction index. One striking feature associated with the magnetism in the scatterer is that particles smaller than the wavelength (Rayleigh size region) can present large extinction cross sections in despite of their small geometric cross sections. This becomes physically possible the presence of morphology-dependent resonances in the electromagnetic energy within the scatterer even in size parameters region smaller than unity. In particular, we show that this time-averaged electromagnetic energy has, in the weak absorption regime, a simple functional relation with the incident wavelength and the scatterer absorption cross section which does not depend on the shape of the scatterer. In the multiple scattering regime, the energy-transport velocity can be estimated from the time-averaged electromagnetic energy stored in a single scatterer. Thereby, the validity of the universal relation between the internal energy-enhancement factor and the absorption cross section respective to an arbitrary scattering center (in the weak absorption regime) implies that the energy-transport velocity in disordered media can be evaluated in a simple way. From this approximation, we obtain that even in the Rayleigh size region the energy-transport velocity in disordered magnetic media is dramatically reduced, which consequently leads to a reduction of the diffusion coefficient of the photons. The analytical and numerical studies of the time-averaged electromagnetic energy within magnetic isotropic spheres and cylinders irradiated by plane waves are our aim in this Master\'s degree dissertation.

La hiérarchisation de la puissance injectée par des sources acoustiques dans une cavité d'avion telle qu'un cockpit, en vol, revêt un caractère majeur dans le but d'en réduire le bruit intérieur. Afin de répondre à ce besoin, la nécessité de considérer la cavité dans son ensemble à l'aide d'une méthode globale se révèle importante. Au cours de cette thèse, une méthode d'identification basée sur une méthode énergétique locale, appelée MES pour Méthode Energétique Simplifiée, est utilisée. En connaissant la géométrie de la cavité, ainsi que l'absorption des matériaux qui la composent, elle permet de déterminer la puissance rayonnée par les différentes sources acoustiques à l'intérieur de la cavité, à l'aide de mesures d'intensité tridimensionnelle, et de densité d'énergie acoustique totale. Afin de tester la méthode dans un cas réel, mesurer ces quantités énergétiques s'avère alors nécessaire. Une sonde acoustique est donc conçue, fabriquée, testée et enfin validée. Basée sur quatre mesures de pressions réalisées autour d'une sphère rigide à l'aide de microphones électrostatiques déportés, elle permet de mesurer la pression et le vecteur vitesse particulaire au centre de la sphère, et d'en déduire alors l'intensité 3D et la densité d'énergie totale. Un démonstrateur est ensuite construit pour réaliser des essais. Il s'agit d'une maquette de cockpit basée sur celui de l'A380. Différents essais acoustiques et vibro-acoustiques permettent alors de démontrer la capacité de l'association formée par la méthode d'identification et la sonde à déterminer la puissance injectée par les différentes sources dans des conditions acoustiques plus ou moins sévères, avec une précision de l'ordre de 2dB. Le post-traitement à l'aide de la MES des flux acoustiques rayonnés ainsi déterminés permet également de reconstruire le champ acoustique dans la cavité, ainsi que de séparer les différentes contributions en des points d'intérêt tels que les têtes pilote et copilote. / Organizing into a hierarchy the power injected by acoustic sources inside an aircraft cavity such as a cockpit, in flight conditions, appears as a crucial stage in orcier to reduce interior noise. To address this need, considering the whole cavity with a global method turns out to be essential. In this work, an identification method based on a local energy method called MES for Simplified Energy Method is used. With the cavity geometry and the absorption characteristics of the materials inside, the method is capable of retrieving the acoustic power radiated by the sources within the cavity from three dimensional intensity vector and energy density measurements. To assess the method in a real test case, measuring these previous energy quantities turns out to be necessary. Thus, an acoustic probe is designed, manufactured, tested and to finish validated. Based on four pressure measurements performed around a hard sphere with remote pre-amplified microphones, the multi-sensor probe is able to compute the pressure and the particle velocity vector at the center of the sphere, and then obtain the 3D intensity, and the total acoustic energy density. A cockpit mock-up based on the A380 cockpit geometry is manufactured to perform tests. Several acoustic and vibro-acoustic tests carried out in the mock-up show the capability of the association composed of the identification method and the probe to extract the acoustic power radiated by the sources, in more or less harsh acoustic conditions, with accuracy close to 2dB. Post-processing the computed injected power allows to reconstruct the acoustic field inside the cavity, and to separate the different sources contributions for sorne points of interest such as the pilot or copilot heads.

Ion irradiation of tetrahedral amorphous carbon (ta-C) thin films induces a carbon phase transformation from the electrically insulating sp3 hybridization into the conducting sp2 hybridization. In this work, a detailed study on the electrical resistivity and the microstructure of areas, irradiated with several ion species at 30 keV energy is presented. Continuous ion bombardment yields a drastic drop of the resistivity as well as significant structural modifications of the evolving sp2 carbon phase. It is shown that the resistivity lowering can be attributed to the degree of graphitization in the film. Furthermore, the structural ordering processes are correlated with the ion deposited energy density. It is therefore revealed that the ion-induced phase transformation in ta-C films is a combination of sp3-to-sp2 conversion of carbon atoms and ion-induced ordering of the microstructure into a more graphite-like arrangement. All experiments were done with focused ion beam (FIB) systems by applying FIB lithography of electrical van-der-Pauw test structures. FIB lithography on ta-C layers is presented as a fast and easy technique for the preparation of electrically active micro- and nanostructures in an insulating carbon matrix.:Contents List of Figures iii List of Tables v List of Abbreviations vii 1. Introduction 1 2. Fundamentals 5 2.1. Ion-solid interactions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.1.1. Scattering and stopping . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.1.2. Ion range distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2.1.3. Target modifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2.1.4. Thermal driven segregation . . . . . . . . . . . . . . . . . . . . . . . . . . 18 2.2. Focused ion beams (FIBs) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 2.2.1. Commercial gallium FIB (Ga + -FIB) . . . . . . . . . . . . . . . . . . . . . 24 2.2.2. Mass-separated FIB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 2.3. Tetrahedral amorphous carbon (ta-C) . . . . . . . . . . . . . . . . . . . . . . . . 26 2.3.1. Composition, microstructure and film properties . . . . . . . . . . . . . . 26 2.3.2. Growth mechanisms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 2.3.3. Electronic properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 3. Experimental 39 3.1. Samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 3.2. Apparatus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 4. Ion induced surface swelling 43 4.1. Fluence and energy dependence . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 4.2. Calculations of the swelling height . . . . . . . . . . . . . . . . . . . . . . . . . . 48 5. Electrical properties of irradiated ta-C 55 5.1. Electrical resistivity of as-implanted ta-C . . . . . . . . . . . . . . . . . . . . . . 55 5.1.1. Resistance of Ga + implanted micropatterns . . . . . . . . . . . . . . . . . 55 5.1.2. Sheet resistance of Ga + irradiated ta-C . . . . . . . . . . . . . . . . . . . 59 5.1.3. Determination of the sp 3 content . . . . . . . . . . . . . . . . . . . . . . . 62 5.1.4. The effect of different ion species . . . . . . . . . . . . . . . . . . . . . . . 65 5.1.5. Low temperature resistivity – The peculiarity of gallium . . . . . . . . . . 71 5.2. The effect of annealing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 5.3. Irradiation at elevated substrate temperatures . . . . . . . . . . . . . . . . . . . . 79 6. The microstructure of irradiated ta-C 87 6.1. Raman investigations of ion irradiated ta-C . . . . . . . . . . . . . . . . . . . . . 88 6.1.1. Fundamentals of Raman spectroscopy on amorphous carbon . . . . . . . . 88 6.1.2. Raman spectra of as-implanted ta-C . . . . . . . . . . . . . . . . . . . . . 93 6.1.3. Thermally driven graphitization of the microstructure . . . . . . . . . . . 98ii Contents 6.1.4. The correlation between microstructure and resistivity . . . . . . . . . . . 101 6.2. TEM investigations of ion irradiated ta-C . . . . . . . . . . . . . . . . . . . . . . 104 7. FIB lithography on ta-C layers 107 7.1. Graphitic nanowires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 7.1.1. Nanowire dimensions – The resolution of FIB lithography . . . . . . . . . 108 7.1.2. Nanowire resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110 7.2. Electrical insulation between conducting structures . . . . . . . . . . . . . . . . . 113 8. Conclusions and Outlook 117 A. Gallium nanoparticles on ta-C layers 121 Bibliography 123

京都大学 / 0048 / 新制・課程博士 / 博士(人間・環境学) / 甲第19071号 / 人博第724号 / 新制||人||174(附属図書館) / 26||人博||724(吉田南総合図書館) / 32022 / 京都大学大学院人間・環境学研究科相関環境学専攻 / (主査)教授 内本 喜晴, 教授 田部 勢津久, 准教授 藤原 直樹 / 学位規則第4条第1項該当 / Doctor of Human and Environmental Studies / Kyoto University / DGAM

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The globally increasing energy demand that results from the rapid development of modern society has created intensive attention towards the importance of energy efficiency. The areas of energy storage and energy conversion have become one of the most important topics in scientific community at present. As new generation energy storage elements, supercapacitors have exhibited promising practical prospects in the information, transportation, electronics and other sectors due to their charge and discharge performance at high rate, high power density as well as long cycle life. Energy density, including gravimetric energy density, areal energy density and volumetric energy density, is one of the most critical indicator evaluating the performance of supercapacitors. The electrochemical performance of supercapacitors depends mainly on the electrochemical activities and kinetic properties of electrode materials. Carbonaceous materials are deemed to be highly promising, and therefore are extensively investigated energy storage materials for supercapacitors because of their environmental friendliness, low-cost production and outstanding chemical inertness during charging-discharging processes. The specific surface area has been long thought to be the main factor influencing the capacitance of carbonaceous materials. However, the pore structure is of similar importance. High specific surface areas are always arising from a high content of micropores. However, pore radii in the sub-nanometer range impede the ionic charge transfer ability significantly and thus cause a damping of capacitance. In this thesis, hierarchical porous carbons and their composite materials were fabricated by using polyacrylonitrile as carbon precursor for a tailored step-by-step pore forming method, including phase inversion, CaCO3 activation and KOH activation. The materials were thoroughly characterized by XRD, SEM, TEM, BET, XPS and Raman spectroscopy to ascertain the chemical and structural features. The electrochemical properties were studied by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS) in detail to analyze the pore effect, which strongly influence their electrochemical properties. Porous carbons with high specific surface areas up to 2315 m2 g-1 and high pore volume of 1.9 cm3·g-1 were prepared. A step-wise pore forming method was employed to ensure a high specific surface area and high content of macro/mesopore at the same time. The relationship between pore structure, electrochemical capacitance and rate capability was investigated by changing the content of micropores. For a same specific surface area, a higher micropore content led to a lower capacitance and poorer rate capability. Based on these results, the capacitance was optimized to be 286.8 F g-1. The areal energy density of the supercapacitors can be improved by increasing the mass loading in a certain area directly. However, insufficient electrochemical reaction may be caused by a lack of unhindered electrical and ionic charge transfer routes, resulting in inefficient material utilization. This problem is addressed by designing hierarchical pore structures with embedded conductive additives. Thus, hierarchical porous carbons were modified by embedding carbon nanotubes (CNTs), followed by coverage with thin layers of birnessite. Owing to the hierarchical pore design and the very high pore volume, the birnessite coverage did not cause pore blocking. At the same time, an intimate contact between carbon and birnessite was established. A high area energy density of 627.8 μWh·cm-2 was obtained based on an optimized mass loading of 13.9 mg cm-2. The volumetric energy density of supercapacitors was determined by the density and porosity of active materials. Similarly, the dense active materials not always generate high specific capacitance because of an increased dead mass. However, too porous active materials do not provide sufficient volumetric capacitance due to a waste of space. Thus, density and porosity must be balanced by hierarchical pore structure design so that all pores are interconnected and can be accessed by ions. At the same time, the content of these pores should be as low as possible to save space. Based on the results, highly hierarchical porous carbons were synthesized and embedded into conductive carbon foam to combine electronic conductivity with ionic transfer. In that way, a volumetric energy density as high as 19.44 µWh cm-3 at a volumetric power density of 500 mW cm-3 was generated.

The desire for energy and resource savings brings magnesium alloys as lightweight materials with high specific strength more and more into the focus. Most structural components are subjected to cyclic loading. In the course of computer aided product development, a numerical prediction of the fatigue life under these conditions must be provided. For this reason, the mechanical properties of the considered material must be examined in detail. Wrought magnesium semifinished products, e.g. magnesium sheet metals, typically reveal strong basal textures and thus, the mechanical behavior considerably differs from that of the well-established magnesium die castings. Magnesium sheet metals reveal a distinct difference in the tensile and compressive yield stress, leading to non-symmetric sigmoidal hysteresis loops within the elasto-plastic load range. These unusual hysteresis shapes are caused by cyclic twinning and detwinning. Furthermore, wrought magnesium alloys reveal pseudoelastic behavior, leading to nonlinear unloading curves. Another interesting effect is the formation of local twin bands during compressive loading. Nevertheless, only little information can be found on the numerical fatigue analysis of wrought magnesium alloys up to now. The aim of this thesis is the investigation of the mechanical properties of wrought magnesium alloys and the development of an appropriate fatigue model. For this purpose, twin roll cast AM50 as well as AZ31B sheet metals and extruded ME21 sheet metals were used. Mechanical tests were carried out to present a comprehensive overview of the quasi-static and cyclic material behavior. The microstructure was captured on sheet metals before and after loading to evaluate the correlation between the microstructure, the texture, and the mechanical properties. Stress- and strain-controlled loading ratios and strain-controlled experiments with variable amplitudes were performed. Tests were carried out along and transverse to the manufacturing direction to consider the influence of the anisotropy. Special focus was given to sigmoidal hysteresis loops and their influence on the fatigue life. A detailed numerical description of hysteresis loops is necessary for numerical fatigue analyses. For this, a one-dimensional phenomenological model was developed for elasto-plastic strain-controlled constant and variable amplitude loading. This model consists of a three-component equation, which considers elastic, plastic, and pseudoelastic strain components. Considering different magnesium alloys, good correlation is reached between numerically and experimentally determined hysteresis loops by means of different constant and variable amplitude load-time functions. For a numerical fatigue life analysis, an energy based fatigue parameter has been developed. It is denoted by “combined strain energy density per cycle” and consists of a summation of the plastic strain energy density per cycle and the 25 % weighted tensile elastic strain energy density per cycle. The weighting represents the material specific mean stress sensitivity. Applying the energy based fatigue parameter on modeled hysteresis loops, the fatigue life is predicted adequately for constant and variable amplitude loading including mean strain and mean stress effects. The combined strain energy density per cycle achieves significantly better results in comparison to conventional fatigue models such as the Smith-Watson-Topper model. The developed phenomenological model in combination with the combined strain energy density per cycle is able to carry out numerical fatigue life analyses on magnesium sheet metals.

Ce travail présente la mise en oeuvre d’un protocole de synthèse de gradients deconcentration dans les oxydes lamellaires riches en Li et en Mn. Le but a été dedévelopper la formation d’oxydes lamellaires riches en Li et Mn au coeur des agrégatssphériques du matériau actif et, en se rapprochant de la surface, d’enrichir lacomposition de l’oxyde lamellaire en Co et en Ni, afin de combiner une forte densitéd’énergie (apportée par le coeur du gradient) et une excellente stabilité thermique etstructurale (apportée par la surface du gradient). La synthèse a été réalisée en deuxétapes, une co-précipitation pour former un carbonate de métaux de transition suivied’une calcination à haute température pour obtenir le matériau actif lithié. L’influencede différents paramètres (pH, débit d’injection, taille du réacteur, composition, …) surla nature du carbonate à gradient de concentration ainsi formé a été étudiée. De lamême façon, le contrôle du ratio Li/M (ici M = Ni, Co, Mn), de la température et de ladurée de calcination s’est révélé important pour parvenir à maintenir le gradient deconcentration dans le matériau lithié. Le ratio Li/M est également déterminant pourcontrôler la nature des matériaux obtenus (lamellaire - spinelle ou lamellaire –lamellaire). Des caractérisations extrêmement pointues, et complexes à mettre enoeuvre, ont été menées afin d’obtenir des informations pertinentes sur la distributiondes phases au sein des agrégats (composition et structure), de la surface au coeur dugradient : différentes techniques de microscopie (EPMA, MEB-EDX et FIB-STEM) ontainsi été largement utilisées. Les matériaux les plus intéressants ont été étudiés enbatteries Lithium-ion avec une électrode de graphite à la négative, les performancesélectrochimiques et la stabilité thermique à l’état chargé de la batterie sont largementdiscutées par rapport à l’état de l’art et notamment au matériau de coeur riche en Li eten Mn. / This work describes in details the implementation of the synthesis protocol for theformation of Li- and Mn-rich layered oxides with concentration-gradients. The purposewas to develop the synthesis of Li- and Mn-rich layered oxides in the bulk of sphericalaggregates of active material and, moving to the surface, to enrich the layered oxides’composition with Co and Ni, in order to combine a high energy density (provided bythe bulk) and an excellent thermal and structural stability (provided by the surface).The synthesis was performed in two steps, a coprecipitation to form a transition metalcarbonate followed by a calcination at high temperature to obtain the lithiated activematerial. The influence of several parameters (pH, feeding rate, size of the reactor,composition …) on the nature of the carbonates formed with concentration-gradientswas studied. Similarly, the control of the Li/M ratio (with M = Ni, Co, Mn) and of thetemperature and duration of calcination was revealed to be important to maintain theconcentration-gradient in the lithiated materials. The Li/M ratio is also the keyparameter to control the nature of the materials obtained (layered - spinel or layered -layered). Advanced characterizations, complex to be implemented, were performed inorder to obtain in-depth information on the distribution of phases within the aggregates(composition and structure), from the bulk to the surface: complementary microscopytechniques (EPMA, SEM-EDS and FIB-STEM) were widely used. The most interestingmaterials were studied in Lithium-ion batteries with graphite at the negative electrode,their electrochemical performance and the thermal stability in the charged state of thebattery were compared to the state of art, and particularly to the bulk Li and Mn-richlayered oxide.

Synthetic vascular grafts are useful to bypass diseased arteries. The long-term failure of synthetic grafts is primarily due to intimal hyperplasia at the anastomotic sites. The accelerated intimal hyperplasia may stem from a compliance mismatch between the host artery and the graft since commercially available synthetic conduits are much stiffer than an artery. The objective of this thesis is to design a method for fabricating a vascular graft that mechanically matches the patients native artery over the expected physiologic range of pressures. The creation of an optimized mechanical graft will hopefully lead to an improvement in patency rates. The mechanical equivalency between the graft and the host artery is defined locally by several criteria including the diameter upon inflation, the elasticity at mean pressure, and axial force. A single parameter mathematical for a thin-walled tube is used to describe of the final mechanical behavior of a synthetic graft. For the general problem, the objective would be to fabricate a mechanics-matching vascular graft for each host artery. Typically, fabrication parameters are set initially and the properties of the fabricated graft are measured. However, by modeling the entire fabrication process and final mechanical properties, it is possible to invert the situation and let the typical output mechanical values be used to define the fabrication parameters. The resultant fabricated graft will then be mechanically matching. As a proof-of-concept, several prototype synthetic grafts were manufactured and characterized by a single Invariant to match a canine artery. The resultant graft equaled the diameter upon inflation, the elasticity at mean pressure, and axial force of the native canine artery within 6%. An alternative to making an individual graft for each artery is also presented. A surgeon may choose the best graft from a set of pre-manufactured grafts, using a computer program algorithm for best fit using two parameters in a neighborhood. The design optimization problem was solved for both canine carotid and human coronary arteries. In conclusion, the overall process of design, fabrication and selection of a mechanics matching synthetic vascular graft is shown to be reliable and robust.