The Experts below are selected from a list of 1992 Experts worldwide ranked by ideXlab platform
Teruo Murakami - One of the best experts on this subject based on the ideXlab platform.
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evaluation of influence of changes in permeability with aging on friction and biphasic behaviors of Artificial hydrogel Cartilage
Biotribology, 2021Co-Authors: Teruo Murakami, Kazuhiro Nakashima, Yoshinori Sawae, Seido Yarimitsu, Nobuo Sakai, Tetsuo Yamaguchi, Atsushi SuzukiAbstract:Abstract Various hydrogels have been developed to use as Artificial Cartilage. Poly(vinyl alcohol) (PVA) hydrogel cross-linked by hydrogen bonds is biocompatible and has similar properties to natural articular Cartilage. For clinical use as Artificial Cartilage, superior tribological performance with low friction and minimal wear are required. In our previous study, three kinds of preparation methods for PVA hydrogels with high water content, i.e., the repeated freeze-thawing (FT) method, the cast-drying (CD) method and the layered hybrid method composed of FT and CD layers were applied. As hybrid gel specimens, (CD on FT) and (FT on CD) gels were prepared. The comparison between experiment and biphasic finite element analysis showed that the frictional behaviors of these PVA hydrogels at slow speed are controlled by their biphasic lubrication mechanism. After that, it was found that the biphasic properties of FT gel with heterogeneous network structure was largely changed after immersion in water for more than 6 years. In this paper, the influence of changes in permeability with aging of FT gel on friction and biphasic behaviors of PVA hydrogels was evaluated by biphasic finite element analysis. As aged FT specimens with lower permeability, four kinds of aged FT specimens with different elastic properties were evaluated. As a result, it is suggested that frictional behavior of PVA FT gels with aging can be improved by lowering of permeability in aged FT gel. Furthermore, it is expected that hybrid gel as CD on aged FT with appropriate elastic modulus can sustain superior low friction.
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Biomimetic Artificial Cartilage: Fibre-reinforcement of PVA hydrogel to promote biphasic lubrication mechanism
Biosurface and Biotribology, 2019Co-Authors: Nobuo Sakai, Yoshinori Sawae, Seido Yarimitsu, Mochimitsu Komori, Teruo MurakamiAbstract:The fibre-reinforced structure in synovial articular Cartilage plays an important role in enhancing the fluid load support in the biphasic lubrication mechanism. Poly(vinyl alcohol) (PVA) hydrogel is a potential biomimetic articular Cartilage material. In this study, PVA hydrogel was reinforced with PVA fibres to improve its frictional properties. By computational analysis, the position of the PVA fibre layer was examined with a migrating contact condition to reduce the friction coefficient. To improve the fibre reinforcement, a method for fibre placement was developed to retain the initial strain of the fibre in the hydrogel matrix. The experimental results showed that the fibre-reinforced PVA hydrogel with a surface fibre layer had a low friction coefficient of 0.031 in pure water. The fibre-reinforced PVA hydrogel successfully reduced friction coefficient.
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Transitional behaviour between biphasic lubrication and soft elastohydrodynamic lubrication of poly(vinyl alcohol) hydrogel using microelectromechanical system pressure sensor
Biosurface and Biotribology, 2018Co-Authors: Nobuo Sakai, Yoshinori Sawae, Seido Yarimitsu, Mochimitsu Komori, Teruo MurakamiAbstract:The soft hydrogel material is expected for a candidate material as biomimetic Artificial Cartilage with synergistic functionalities of adaptive multimode lubrication. In boundary lubrication mode of hydrogel material, the biphasic lubrication mechanism cooperatively exerts its functionality. In hydrodynamic lubrication mode, it is preferable that the lubricating surfaces be impermeable to trap the fluid pressure in contact surfaces, whereas the actual biphasic material like a hydrogel is a permeable material with surface porosity. It is indicated that the interstitial fluid pressurisation in the permeable biphasic material can contribute to significant fluid load support under lower sliding speed condition. So, the authors examined how the contrary fluid pressure effect appears in the transition from the boundary lubrication mode to soft elastohydrodynamic lubrication mode. In the experiment, a small pressure sensor was utilised to measure the in-situ fluid pressure in sliding condition. Although the experimental condition of this study was selective, the result showed a possibility of the negative effect of the biphasic surface, in which the permeable surface diminished the hydrodynamic fluid pressure. This means that one should manage and enhance the biphasic lubrication abilities in wide operation range when the hydrogel material was used as a load bearing material.
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superior lubrication ability and minimal wear of poly vinyl alcohol hybrid hydrogel as a novel material application for Artificial Cartilage
Orthopaedic Proceedings, 2018Co-Authors: Teruo Murakami, Kazuhiro Nakashima, Yoshinori Sawae, Seido Yarimitsu, Nobuo Sakai, Tetsuo Yamaguchi, Atsushi SuzukiAbstract:Total hip and knee joint prostheses composed of ultra-high molecular weight polyethylene (UHMWPE) and metal or ceramics have been widely applied. Efficacious treatments such as crosslinking, additi...
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superior lubrication mechanism in poly vinyl alcohol hybrid gel as Artificial Cartilage
Proceedings of the Institution of Mechanical Engineers Part J: Journal of Engineering Tribology, 2017Co-Authors: Kazuhiro Nakashima, Yoshinori Sawae, Seido Yarimitsu, Nobuo Sakai, Teruo Murakami, Tetsuo Yamaguchi, Atsushi SuzukiAbstract:With recent progress of material technologies, the wear resistance of ultra-high molecular weight polyethylene for total joint prostheses has been improved, but under severe conditions friction and...
Atsushi Suzuki - One of the best experts on this subject based on the ideXlab platform.
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evaluation of influence of changes in permeability with aging on friction and biphasic behaviors of Artificial hydrogel Cartilage
Biotribology, 2021Co-Authors: Teruo Murakami, Kazuhiro Nakashima, Yoshinori Sawae, Seido Yarimitsu, Nobuo Sakai, Tetsuo Yamaguchi, Atsushi SuzukiAbstract:Abstract Various hydrogels have been developed to use as Artificial Cartilage. Poly(vinyl alcohol) (PVA) hydrogel cross-linked by hydrogen bonds is biocompatible and has similar properties to natural articular Cartilage. For clinical use as Artificial Cartilage, superior tribological performance with low friction and minimal wear are required. In our previous study, three kinds of preparation methods for PVA hydrogels with high water content, i.e., the repeated freeze-thawing (FT) method, the cast-drying (CD) method and the layered hybrid method composed of FT and CD layers were applied. As hybrid gel specimens, (CD on FT) and (FT on CD) gels were prepared. The comparison between experiment and biphasic finite element analysis showed that the frictional behaviors of these PVA hydrogels at slow speed are controlled by their biphasic lubrication mechanism. After that, it was found that the biphasic properties of FT gel with heterogeneous network structure was largely changed after immersion in water for more than 6 years. In this paper, the influence of changes in permeability with aging of FT gel on friction and biphasic behaviors of PVA hydrogels was evaluated by biphasic finite element analysis. As aged FT specimens with lower permeability, four kinds of aged FT specimens with different elastic properties were evaluated. As a result, it is suggested that frictional behavior of PVA FT gels with aging can be improved by lowering of permeability in aged FT gel. Furthermore, it is expected that hybrid gel as CD on aged FT with appropriate elastic modulus can sustain superior low friction.
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superior lubrication ability and minimal wear of poly vinyl alcohol hybrid hydrogel as a novel material application for Artificial Cartilage
Orthopaedic Proceedings, 2018Co-Authors: Teruo Murakami, Kazuhiro Nakashima, Yoshinori Sawae, Seido Yarimitsu, Nobuo Sakai, Tetsuo Yamaguchi, Atsushi SuzukiAbstract:Total hip and knee joint prostheses composed of ultra-high molecular weight polyethylene (UHMWPE) and metal or ceramics have been widely applied. Efficacious treatments such as crosslinking, additi...
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superior lubrication mechanism in poly vinyl alcohol hybrid gel as Artificial Cartilage
Proceedings of the Institution of Mechanical Engineers Part J: Journal of Engineering Tribology, 2017Co-Authors: Kazuhiro Nakashima, Yoshinori Sawae, Seido Yarimitsu, Nobuo Sakai, Teruo Murakami, Tetsuo Yamaguchi, Atsushi SuzukiAbstract:With recent progress of material technologies, the wear resistance of ultra-high molecular weight polyethylene for total joint prostheses has been improved, but under severe conditions friction and...
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development of pva hydrogels with superior lubricity for Artificial Cartilage
2017Co-Authors: Atsushi Suzuki, Saori Sasaki, Teruo MurakamiAbstract:Physically cross-linked poly(vinyl alcohol) (PVA) gels are versatile biomaterials with their excellent biocompatibility and mechanical strength. Since the late 1970s, the semicrystalline PVA gels prepared by a freeze-thawing method (FT gel) have been extensively studied in characterizing the structural and functional properties for practical applications, such as Artificial hydrogel Cartilage. Recently, a simple preparation method for a physically cross-linked PVA gel by a cast-drying method (CD gel) was reported. Although the network nanostructures are similar, CD gels are transparent and elastic, while FT gels are opaque and less elastic. The crystallization conditions of these systems have been investigated; the gels become highly swollen and rigid by the selection of optimum preparation conditions. In this chapter, the mechanical properties of FT and CD gels, such as tearing energy, sliding friction, and abrasion loss, are reviewed in connection with the nano- and microstructures of physical PVA gels. The tribological properties of FT and CD gels are compared with that of natural Cartilage. Based on experimental results, simple preparation methods to improve the mechanical and lubrication properties of physically cross-linked PVA gels are presented, and the mechanism of superior lubricity in newly developed PVA gels for Artificial hydrogel Cartilage is discussed.
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SUPERIOR LUBRICATION ABILITY AND MINIMAL WEAR OF POLY(VINYL ALCOHOL) HYBRID HYDROGEL AS A NOVEL MATERIAL APPLICATION FOR Artificial Cartilage
Journal of Bone and Joint Surgery-british Volume, 2016Co-Authors: Teruo Murakami, Kazuhiro Nakashima, Yoshinori Sawae, Seido Yarimitsu, Nobuo Sakai, Tetsuo Yamaguchi, Atsushi SuzukiAbstract:Total hip and knee joint prostheses composed of ultra-high molecular weight polyethylene (UHMWPE) and metal or ceramics have been widely applied. Efficacious treatments such as crosslinking, addition of vitamin E and phospholipid coating to UHMWPE have reduced wear and extended the life of joint prostheses. However, wear problems have not yet been completely solved for cases involving severe conditions, where direct contact can occur in mixed or boundary lubrication. In contrast, extremely low friction and minimum wear are maintained for a lifetime in healthy natural synovial joints containing articular Cartilage with superior lubricity. Accordingly, joint prostheses containing Artificial hydrogel Cartilage with properties similar to those of articular Cartilage are expected to show superior tribological functions. In establishing the function of Artificial hydrogel Cartilage as a novel material for joint prostheses, the tribological properties of hydrogel materials used and synergistic performance with synovia constituents are both important. In this study, the lubrication ability and wear resistance properties of poly(vinyl alcohol) (PVA) hydrogels were evaluated by differences in friction and wear properties in reciprocating tests lubricated with saline and simulated synovial fluid. Biphasic finite element (FE) analysis was applied to elucidate the role of biphasic lubrication mechanism in hydrogels. As biocompatible Artificial hydrogel Cartilage materials, three PVA hydrogels were prepared using the repeated freeze-thawing (FT) method, the cast-drying (CD) method and the hybrid method for laminated gel of FT on CD, which are physically crosslinked with hydrogen bonding but differ in terms of structure and mechanical properties. First the frictional behavior of the ellipsoidal PVA hydrogel specimens was examined in reciprocating tests against a glass plate, which corresponds to simplified knee prosthesis model (Fig.1), with a sliding speed of 20 mm/s under constant continuous loading. As shown in Fig.1, the three hydrogels exhibited different frictional behaviors in a saline solution. It is noteworthy that the hybrid gel maintained very low friction until the end of test. The CD gel showed slightly higher friction and a gradual increase. Meanwhile, the FT gel showed initial medium friction and a gradual increase. Time-dependent frictional behavior was clarified with biphasic lubrication mechanism via biphasic FE analysis. Contact surface observation showed minimal wear without scratches for hybrid gel in saline. Next, simulated synovial fluid composed of 0.5 wt% hyaluronic acid (HA, molecular weight: 920,000 Da), 1.4 wt% albumin, 0.7 wt% gamma-globulin and 0.01 wt% L-alpha dipalmitoylphosphatidylcholine (DPPC), was used to evaluate tribological performance of these gels in physiological condition. As shown in Fig.2, PVA hydrogels in simulated synovial fluid exhibited very low friction, with hybrid gel showing an extremely low friction coefficient of 0.003 in the test. These friction differences were sustained by biphasic FE analysis. Hybrid gel further showed very little wear (Fig.3), which is favorable in terms of hydrogel durability. These results indicate the importance of superior lubricity and wear resistance of PVA hybrid gel for the clinical application of Artificial hydrogel Cartilage in joint prostheses.
Yoshinori Sawae - One of the best experts on this subject based on the ideXlab platform.
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evaluation of influence of changes in permeability with aging on friction and biphasic behaviors of Artificial hydrogel Cartilage
Biotribology, 2021Co-Authors: Teruo Murakami, Kazuhiro Nakashima, Yoshinori Sawae, Seido Yarimitsu, Nobuo Sakai, Tetsuo Yamaguchi, Atsushi SuzukiAbstract:Abstract Various hydrogels have been developed to use as Artificial Cartilage. Poly(vinyl alcohol) (PVA) hydrogel cross-linked by hydrogen bonds is biocompatible and has similar properties to natural articular Cartilage. For clinical use as Artificial Cartilage, superior tribological performance with low friction and minimal wear are required. In our previous study, three kinds of preparation methods for PVA hydrogels with high water content, i.e., the repeated freeze-thawing (FT) method, the cast-drying (CD) method and the layered hybrid method composed of FT and CD layers were applied. As hybrid gel specimens, (CD on FT) and (FT on CD) gels were prepared. The comparison between experiment and biphasic finite element analysis showed that the frictional behaviors of these PVA hydrogels at slow speed are controlled by their biphasic lubrication mechanism. After that, it was found that the biphasic properties of FT gel with heterogeneous network structure was largely changed after immersion in water for more than 6 years. In this paper, the influence of changes in permeability with aging of FT gel on friction and biphasic behaviors of PVA hydrogels was evaluated by biphasic finite element analysis. As aged FT specimens with lower permeability, four kinds of aged FT specimens with different elastic properties were evaluated. As a result, it is suggested that frictional behavior of PVA FT gels with aging can be improved by lowering of permeability in aged FT gel. Furthermore, it is expected that hybrid gel as CD on aged FT with appropriate elastic modulus can sustain superior low friction.
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Biomimetic Artificial Cartilage: Fibre-reinforcement of PVA hydrogel to promote biphasic lubrication mechanism
Biosurface and Biotribology, 2019Co-Authors: Nobuo Sakai, Yoshinori Sawae, Seido Yarimitsu, Mochimitsu Komori, Teruo MurakamiAbstract:The fibre-reinforced structure in synovial articular Cartilage plays an important role in enhancing the fluid load support in the biphasic lubrication mechanism. Poly(vinyl alcohol) (PVA) hydrogel is a potential biomimetic articular Cartilage material. In this study, PVA hydrogel was reinforced with PVA fibres to improve its frictional properties. By computational analysis, the position of the PVA fibre layer was examined with a migrating contact condition to reduce the friction coefficient. To improve the fibre reinforcement, a method for fibre placement was developed to retain the initial strain of the fibre in the hydrogel matrix. The experimental results showed that the fibre-reinforced PVA hydrogel with a surface fibre layer had a low friction coefficient of 0.031 in pure water. The fibre-reinforced PVA hydrogel successfully reduced friction coefficient.
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Transitional behaviour between biphasic lubrication and soft elastohydrodynamic lubrication of poly(vinyl alcohol) hydrogel using microelectromechanical system pressure sensor
Biosurface and Biotribology, 2018Co-Authors: Nobuo Sakai, Yoshinori Sawae, Seido Yarimitsu, Mochimitsu Komori, Teruo MurakamiAbstract:The soft hydrogel material is expected for a candidate material as biomimetic Artificial Cartilage with synergistic functionalities of adaptive multimode lubrication. In boundary lubrication mode of hydrogel material, the biphasic lubrication mechanism cooperatively exerts its functionality. In hydrodynamic lubrication mode, it is preferable that the lubricating surfaces be impermeable to trap the fluid pressure in contact surfaces, whereas the actual biphasic material like a hydrogel is a permeable material with surface porosity. It is indicated that the interstitial fluid pressurisation in the permeable biphasic material can contribute to significant fluid load support under lower sliding speed condition. So, the authors examined how the contrary fluid pressure effect appears in the transition from the boundary lubrication mode to soft elastohydrodynamic lubrication mode. In the experiment, a small pressure sensor was utilised to measure the in-situ fluid pressure in sliding condition. Although the experimental condition of this study was selective, the result showed a possibility of the negative effect of the biphasic surface, in which the permeable surface diminished the hydrodynamic fluid pressure. This means that one should manage and enhance the biphasic lubrication abilities in wide operation range when the hydrogel material was used as a load bearing material.
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superior lubrication ability and minimal wear of poly vinyl alcohol hybrid hydrogel as a novel material application for Artificial Cartilage
Orthopaedic Proceedings, 2018Co-Authors: Teruo Murakami, Kazuhiro Nakashima, Yoshinori Sawae, Seido Yarimitsu, Nobuo Sakai, Tetsuo Yamaguchi, Atsushi SuzukiAbstract:Total hip and knee joint prostheses composed of ultra-high molecular weight polyethylene (UHMWPE) and metal or ceramics have been widely applied. Efficacious treatments such as crosslinking, additi...
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superior lubrication mechanism in poly vinyl alcohol hybrid gel as Artificial Cartilage
Proceedings of the Institution of Mechanical Engineers Part J: Journal of Engineering Tribology, 2017Co-Authors: Kazuhiro Nakashima, Yoshinori Sawae, Seido Yarimitsu, Nobuo Sakai, Teruo Murakami, Tetsuo Yamaguchi, Atsushi SuzukiAbstract:With recent progress of material technologies, the wear resistance of ultra-high molecular weight polyethylene for total joint prostheses has been improved, but under severe conditions friction and...
Yeqiao Meng - One of the best experts on this subject based on the ideXlab platform.
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dual anchoring intercalation structure and enhanced bioactivity of poly vinyl alcohol graphene oxide hydroxyapatite nanocomposite hydrogels as Artificial Cartilage replacement
Industrial & Engineering Chemistry Research, 2020Co-Authors: Jinlong Cao, Yeqiao Meng, Xiaowen ZhaoAbstract:Through the dual-anchoring effect, hydroxyapatite (HA) molecules were intercalated into graphene oxide (GO) layers to form a GO–PEG–HA hybrid, and PVA/GO–PEG–HA nanocomposite hydrogels were prepare...
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3d printing of a poly vinyl alcohol based nano composite hydrogel as an Artificial Cartilage replacement and the improvement mechanism of printing accuracy
Journal of Materials Chemistry B, 2020Co-Authors: Yeqiao Meng, Jinlong Cao, Yue ChenAbstract:Inspired by the gradient structure of articular Cartilage, a poly(vinyl alcohol) (PVA)-based composite hydrogel with a biomimetic gradient structure as an Artificial Cartilage replacement was constructed by an extrusion 3D printing technique. The influence of the concentration and composition of the PVA-based solution on its rheological behavior and printability was studied, and the improvement mechanism for the 3D printing accuracy of the hydrogel was explored: introduction of GO or GO–HA gave rise to weakened inter-molecular hydrogen bonds and reduced entanglement density simultaneously, and the dynamic viscosity was highly improved. Therefore, the solution exhibited enhanced shear-thinning behavior in the printing shear rate range and a reduced Barus effect, thus highly improving the printability and printing accuracy of the samples. The 3D printing of PVA hydrogels was successfully achieved, and the printed biomimetic gradient samples possessed suitable compressive and tribological properties, which showed promising potential in the precise customized repair of Artificial Cartilage.
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in situ cross linking of poly vinyl alcohol graphene oxide polyethylene glycol nanocomposite hydrogels as Artificial Cartilage replacement intercalation structure unconfined compressive behavior and biotribological behaviors
Journal of Physical Chemistry C, 2018Co-Authors: Yeqiao Meng, Phil Coates, Peter C TwiggAbstract:Poly(vinyl alcohol) (PVA)/graphene oxide (GO) nanocomposite hydrogel as Artificial Cartilage replacement was prepared via freezing/thawing method by introducing polyethylene glycol (PEG). Efficient grafting of PVA molecules onto GO surface was realized by formation of hydrogen bonding, resulting in exfoliation and uniform distribution of GO in PVA matrix. By introduction of appropriate content of GO, the increased crystalline regions of PVA and the formation of GO centered second network structure led to the increase of the storage modulus and effective cross-linking density. And therefore the mechanical strength and toughness of the composite hydrogel were improved simultaneously: the tensile strength, elongation at break, and compressive modulus showed approximately 200%, 40%, and 100% increase of the neat PVA hydrogel. Besides, for the sample with 1.5 wt % GO content, the maximum force retention and dynamic stiffness were improved remarkably in the process of sinusoidal cyclic compression, and the comp...
Seido Yarimitsu - One of the best experts on this subject based on the ideXlab platform.
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evaluation of influence of changes in permeability with aging on friction and biphasic behaviors of Artificial hydrogel Cartilage
Biotribology, 2021Co-Authors: Teruo Murakami, Kazuhiro Nakashima, Yoshinori Sawae, Seido Yarimitsu, Nobuo Sakai, Tetsuo Yamaguchi, Atsushi SuzukiAbstract:Abstract Various hydrogels have been developed to use as Artificial Cartilage. Poly(vinyl alcohol) (PVA) hydrogel cross-linked by hydrogen bonds is biocompatible and has similar properties to natural articular Cartilage. For clinical use as Artificial Cartilage, superior tribological performance with low friction and minimal wear are required. In our previous study, three kinds of preparation methods for PVA hydrogels with high water content, i.e., the repeated freeze-thawing (FT) method, the cast-drying (CD) method and the layered hybrid method composed of FT and CD layers were applied. As hybrid gel specimens, (CD on FT) and (FT on CD) gels were prepared. The comparison between experiment and biphasic finite element analysis showed that the frictional behaviors of these PVA hydrogels at slow speed are controlled by their biphasic lubrication mechanism. After that, it was found that the biphasic properties of FT gel with heterogeneous network structure was largely changed after immersion in water for more than 6 years. In this paper, the influence of changes in permeability with aging of FT gel on friction and biphasic behaviors of PVA hydrogels was evaluated by biphasic finite element analysis. As aged FT specimens with lower permeability, four kinds of aged FT specimens with different elastic properties were evaluated. As a result, it is suggested that frictional behavior of PVA FT gels with aging can be improved by lowering of permeability in aged FT gel. Furthermore, it is expected that hybrid gel as CD on aged FT with appropriate elastic modulus can sustain superior low friction.
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Biomimetic Artificial Cartilage: Fibre-reinforcement of PVA hydrogel to promote biphasic lubrication mechanism
Biosurface and Biotribology, 2019Co-Authors: Nobuo Sakai, Yoshinori Sawae, Seido Yarimitsu, Mochimitsu Komori, Teruo MurakamiAbstract:The fibre-reinforced structure in synovial articular Cartilage plays an important role in enhancing the fluid load support in the biphasic lubrication mechanism. Poly(vinyl alcohol) (PVA) hydrogel is a potential biomimetic articular Cartilage material. In this study, PVA hydrogel was reinforced with PVA fibres to improve its frictional properties. By computational analysis, the position of the PVA fibre layer was examined with a migrating contact condition to reduce the friction coefficient. To improve the fibre reinforcement, a method for fibre placement was developed to retain the initial strain of the fibre in the hydrogel matrix. The experimental results showed that the fibre-reinforced PVA hydrogel with a surface fibre layer had a low friction coefficient of 0.031 in pure water. The fibre-reinforced PVA hydrogel successfully reduced friction coefficient.
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Transitional behaviour between biphasic lubrication and soft elastohydrodynamic lubrication of poly(vinyl alcohol) hydrogel using microelectromechanical system pressure sensor
Biosurface and Biotribology, 2018Co-Authors: Nobuo Sakai, Yoshinori Sawae, Seido Yarimitsu, Mochimitsu Komori, Teruo MurakamiAbstract:The soft hydrogel material is expected for a candidate material as biomimetic Artificial Cartilage with synergistic functionalities of adaptive multimode lubrication. In boundary lubrication mode of hydrogel material, the biphasic lubrication mechanism cooperatively exerts its functionality. In hydrodynamic lubrication mode, it is preferable that the lubricating surfaces be impermeable to trap the fluid pressure in contact surfaces, whereas the actual biphasic material like a hydrogel is a permeable material with surface porosity. It is indicated that the interstitial fluid pressurisation in the permeable biphasic material can contribute to significant fluid load support under lower sliding speed condition. So, the authors examined how the contrary fluid pressure effect appears in the transition from the boundary lubrication mode to soft elastohydrodynamic lubrication mode. In the experiment, a small pressure sensor was utilised to measure the in-situ fluid pressure in sliding condition. Although the experimental condition of this study was selective, the result showed a possibility of the negative effect of the biphasic surface, in which the permeable surface diminished the hydrodynamic fluid pressure. This means that one should manage and enhance the biphasic lubrication abilities in wide operation range when the hydrogel material was used as a load bearing material.
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superior lubrication ability and minimal wear of poly vinyl alcohol hybrid hydrogel as a novel material application for Artificial Cartilage
Orthopaedic Proceedings, 2018Co-Authors: Teruo Murakami, Kazuhiro Nakashima, Yoshinori Sawae, Seido Yarimitsu, Nobuo Sakai, Tetsuo Yamaguchi, Atsushi SuzukiAbstract:Total hip and knee joint prostheses composed of ultra-high molecular weight polyethylene (UHMWPE) and metal or ceramics have been widely applied. Efficacious treatments such as crosslinking, additi...
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superior lubrication mechanism in poly vinyl alcohol hybrid gel as Artificial Cartilage
Proceedings of the Institution of Mechanical Engineers Part J: Journal of Engineering Tribology, 2017Co-Authors: Kazuhiro Nakashima, Yoshinori Sawae, Seido Yarimitsu, Nobuo Sakai, Teruo Murakami, Tetsuo Yamaguchi, Atsushi SuzukiAbstract:With recent progress of material technologies, the wear resistance of ultra-high molecular weight polyethylene for total joint prostheses has been improved, but under severe conditions friction and...
