Superlubricity Of Molybdenum Disulfide Subjected To Large Compressive Strains,
2022
Guangxi Key Laboratory for Relativistic Astrophysics, Department of Physics, Guangxi University, Nanning 530004, China
Superlubricity Of Molybdenum Disulfide Subjected To Large Compressive Strains, Shengcong Wu, Zhisen Meng, Xiaoma Tao, Zhao Wang
Friction
The friction between a molybdenum disulphide (MoS2) nanoflake and a MoS2 substrate was analyzed using a modified Tomlinson model based on atomistic force fields. The calculations performed in the study suggest that large deformations in the substrate can induce a dramatic decrease in the friction between the nanoflake and the substrate to produce the so-called superlubricity. The coefficient of friction decreases by 1-4 orders of magnitude when a high strain exceeding 0.1 is applied. This friction reduction is strongly anisotropic. For example, the reduction is most pronounced in the compressive regime when the nanoflake slides along the …
New Analytical Model Of Elastic-Plastic Contact For Three- Dimensional Rough Surfaces Considering Interaction Of Asperities,
2022
State Key Laboratory of High Performance Complex Manufacturing, Central South University, Changsha 410083, China
New Analytical Model Of Elastic-Plastic Contact For Three- Dimensional Rough Surfaces Considering Interaction Of Asperities, Yuqin Wen, Jinyuan Tang, Wei Zhou, Lin Li, Caichao Zhu
Friction
The contact calculation of three-dimensional real rough surfaces is the frontier field of tribology and surface science. In this study, we consider the interaction and elastic-plastic deformation characteristics of asperities and further, propose an analytical contact calculation method for rough surfaces considering the interaction of asperities. Based on the watershed algorithm, the rough surface is segmented and the asperities are reconstructed into ellipsoids. According to the height relationship between the asperities, the definition of the deformation reference height of the matrix between each couple of asperities is provided. Subsequently, the calculation formula of the substrate deformation is provided according to …
Gelatin-Based Composite Hydrogels With Biomimetic Lubrication And Sustained Drug Release,
2022
State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China;School of Chemical and Biological Engineering, Shandong University of Science and Technology, Qingdao 266590, China
Gelatin-Based Composite Hydrogels With Biomimetic Lubrication And Sustained Drug Release, Kuan Zhang, Jielai Yang, Yulong Sun, Yi Wang, Jing Liang, Jing Luo, Wenguo Cui, Lianfu Deng, Xiangyang Xu, Bo Wang, Hongyu Zhang
Friction
The occurrence of osteoarthritis is closely related to progressive and irreversible destruction of the articular cartilage, which increases the friction significantly and causes further inflammation of the joint. Thus, a scaffold for articular cartilage defects should be developed via lubrication restoration and drug intervention. In this study, we successfully synthesized gelatin-based composite hydrogels, namely GelMA-PAM-PMPC, with the properties of biomimetic lubrication and sustained drug release by photopolymerization of methacrylic anhydride modified gelatin (GelMA), acrylamide (AM), and 2-methacryloyloxyethyl phosphorylcholine (MPC). Tribological test showed that the composite hydrogels remarkably enhanced lubrication due to the hydration lubrication mechanism, where a tenacious hydration shell …
Probing The Nanofriction Of Non-Halogenated Phosphonium- Based Ionic Liquid Additives In Glycol Ether Oil On Titanium Surface,
2022
Herbert Gleiter Institute of Nanoscience, Department of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
Probing The Nanofriction Of Non-Halogenated Phosphonium- Based Ionic Liquid Additives In Glycol Ether Oil On Titanium Surface, Xiuhua Qiu, Linghong Lu, Zhenyu Qu, Jiongtao Liao, Qi Fan, Faiz Ullah Shah, Wenling Zhang, Rong An
Friction
The nanofrictional behavior of non-halogentated phosphonium-based ionic liquids (ILs) mixed with diethylene glycol dibutyl ether in the molar ratios of 1:10 and 1:70 was investigated on the titanium (Ti) substrate using atomic force microscopy (AFM). A significant reduction is observed in the friction coefficient μ for the IL-oil mixtures with a higher IL concentration (1:10, μ ~ 0.05), compared to that for the lower concentration 1:70 (μ ~ 0.1). AFM approaching force-distance curves and number density profiles for IL-oil mixtures with a higher concentration revealed that the IL preferred to accumulate at the surface forming IL-rich layered structures. The ordered …
Multiscale Friction Model For Hot Sheet Metal Forming,
2022
Tata Steel, Research & Development, CA Ijmuiden 1970, the Netherlands
Multiscale Friction Model For Hot Sheet Metal Forming, Jenny Venema, Javad Hazrati, Eisso Atzema, David Matthews, Ton Van Den Boogaard
Friction
The accurate description of friction is critical in the finite element (FE) simulation of the sheet metal forming process. Usually, friction is oversimplified through the use of a constant Coulomb friction coefficient. In this study, the application of an existing multiscale friction model is extended to the hot stamping process. The model accounts for the effects of tool and sheet metal surface topography as well as the evolution of contact pressure, temperature, and bulk strain during hot stamping. Normal load flattening and strip drawing experiments are performed to calibrate the model. The results show that the model can relatively well …
Mechanical Properties Of Graphene Oxide-Silk Fibroin Bionanofilms Via Nanoindentation Experiments And Finite Element Analysis,
2022
School of Mechanical Engineering, Chung-Ang University, Seoul 06974, Republic of Korea
Mechanical Properties Of Graphene Oxide-Silk Fibroin Bionanofilms Via Nanoindentation Experiments And Finite Element Analysis, Hyeonho Cho, Joonho Lee, Hyundo Hwang, Woonbong Hwang, Jin-Gyun Kim, Sunghan Kim
Friction
Understanding the mechanical properties of bionanofilms is important in terms of identifying their durability. The primary focus of this study is to examine the effect of water vapor annealed silk fibroin on the indentation modulus and hardness of graphene oxide-silk fibroin (GO-SF) bionanofilms through nanoindentation experiments and finite element analysis (FEA). The GO-SF bionanofilms were fabricated using the layer-by-layer technique. The water vapor annealing process was employed to enhance the interfacial properties between the GO and SF layers, and the mechanical properties of the GO-SF bionanofilms were found to be affected by this process. By employing water vapor annealing, the …
Differences In Nano-Topography And Tribochemistry Of Zddp Tribofilms From Variations In Contact Configuration With Steel And Dlc Surfaces,
2022
Laboratory for Tribology and Interface Nanotechnology, Faculty of Mechanical Engineering, University of Ljubljana, Ljubljana 1000, Slovenia
Differences In Nano-Topography And Tribochemistry Of Zddp Tribofilms From Variations In Contact Configuration With Steel And Dlc Surfaces, Lucija Čoga, Somayeh Akbari, Janez Kovač, Mitjan Kalin
Friction
In this work, we evaluated the effect of the counter-body material (the same or dissimilar) and contact configuration (moving or stationary body), at similar contact tribological conditions, on the tribochemical and nanotopography characteristics of adsorbed surface films. Zinc dialkyldithiophosphate (ZDDP), the best performing anti-wear additive, was used in self-mated steel/steel and DLC/DLC contacts, which were compared with mixed steel/DLC and DLC/steel contacts in 1-h and 6-h sliding tests. The macroscale (tribometer) and nanoscale (atomic force microscopy) friction, thickness, topography, and chemical (attenuated total reflection- Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy) properties of the tribofilms were studied. The results …
A Review Of The Bio-Tribology Of Medical Devices,
2022
School of Mechanical Engineering, Southwest Jiaotong University, Chengdu 610031, China
A Review Of The Bio-Tribology Of Medical Devices, Xiaogang Zhang, Yali Zhang, Zhongmin Jin
Friction
Numerous medical devices have been applied for the treatment or alleviation of various diseases. Tribological issues widely exist in those medical devices and play vital roles in determining their performance and service life. In this review, the bio-tribological issues involved in commonly used medical devices are identified, including artificial joints, fracture fixation devices, skin-related devices, dental restoration devices, cardiovascular devices, and surgical instruments. The current understanding of the bio-tribological behavior and mechanism involved in those devices is summarized. Recent advances in the improvement of tribological properties are examined. Challenges and future developments for the prospective of bio-tribological performance are highlighted.
Corrosion-Wear Behavior Of A Biocompatible Magnesium Matrix Composite In Simulated Body Fluid,
2022
College of Materials Science and Engineering, Hunan University, Changsha 410082, China
Corrosion-Wear Behavior Of A Biocompatible Magnesium Matrix Composite In Simulated Body Fluid, Jinlong Su, Jie Teng, Zili Xu, Yuan Li
Friction
Magnesium matrix composites are a new generation of biocompatible implant materials, but they will inevitably undergo simultaneous wear and corrosion in the human body. In this study, hydroxyapatite (Ca10(PO4)6(OH)2, HA) is used in a magnesium matrix composite to study its effects on the corrosion-wear behavior. Two samples (a magnesium alloy composed of Mg, Zn, and Zr (ZK60) alloy and ZK60/10HA composite) were fabricated using the powder metallurgy (PM) process. Their corrosion-wear behavior was investigated using the sliding wear test in a simulated body fluid (SBF). At all the sliding velocities tested, the …
Electrostatic Attraction Caused By Triboelectrification In Climbing Geckos,
2022
College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
Electrostatic Attraction Caused By Triboelectrification In Climbing Geckos, Yi Song, Zhouyi Wang, Yang Li, Zhendong Dai
Friction
Adhesion achieved through feet setae is fundamental for gecko agilely maneuvering. Although diverse hypotheses have been proposed, none of them thoroughly explains the setae function, implying a kind of hybrid-mechanism-based adhesion in geckos. In addition to van der Waals interactions and capillary force, the electrostatic attraction that emerges from triboelectrification was suggested as a component of setae adhesion. Nevertheless, the contribution by electrostatic attraction to the total setae attachment is still controversial. In this study, we analyzed the occurrence of electrostatic attraction at gecko setae through experiments and model analyses. By touching the substrates with only ~1/70th of the …
Fibers Reinforced Composite Hydrogels With Improved Lubrication And Load-Bearing Capacity,
2022
Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China;School of Mechanical Engineering, Lanzhou Jiaotong University, Lanzhou 730050, China
Fibers Reinforced Composite Hydrogels With Improved Lubrication And Load-Bearing Capacity, Jiawei Li, Luyao Gao, Rongnian Xu, Shuanhong Ma, Zhengfeng Ma, Yanhua Liu, Yang Wu, Libang Feng, Meirong Cai, Feng Zhou
Friction
Hydrogels as one kind of soft materials with a typical three-dimensional (3D) hydrophilic network have been getting great attention in the field of biolubrication. However, traditional hydrogels commonly show poor tribology performance under high-load conditions because of their poor mechanical strength and toughness. Herein, pure chemical-crosslinking hydrogels mixed with different types of the micron-scale fibers can meet the requirements of strength and toughness for biolubrication materials, meanwhile the corresponding tribology performance improves significantly. In a typical case, three kinds of reinforcement matrix including needle-punched fibers, alginate fibers, and cottons are separately combined with Poly(n-vinyl pyrrolidone)-poly(2-hydroxyethyl methacrylate (PVP-PHEMA) hydrogels to prepare …
Biodegradable Lubricating Mesoporous Silica Nanoparticles For Osteoarthritis Therapy,
2022
State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China;College of Mining, Guizhou University, Guiyang 550025, China
Biodegradable Lubricating Mesoporous Silica Nanoparticles For Osteoarthritis Therapy, Li Wan, Yi Wang, Xiaolong Tan, Yulong Sun, Jing Luo, Hongyu Zhang
Friction
Osteoarthritis is characterized by lubrication failure of the articular cartilage and severe inflammation of the joint capsule. Lubricating mesoporous silica nanoparticles (MSNs) have been developed for the treatment of osteoarthritis based on enhanced lubrication and local drug delivery. However, MSNs are difficult to degrade in vivo in a short time, resulting in potential toxic effect due to bioaccumulation. In this study, biodegradable MSNs (bMSNs) were prepared through an oil-water biphase stratification method, and modified with poly(2-methacryloyloxyethyl phosphocholine) (PMPC) to synthesize lubricating drug-loaded nanoparticles (bMSNs-NH2@PMPC) by photopolymerization. The in vitro degradation test demonstrated that the bMSNs and bMSNs-NH2 …
Regulation Mechanism Of Biomolecule Interaction Behaviors On The Superlubricity Of Hydrophilic Polymer Coatings,
2022
Institute of Advanced Manufacturing and Intelligent Technology, Beijing University of Technology, Beijing 100124, China;Beijing Key Laboratory of Advanced Manufacturing Technology, Beijing University of Technology, Beijing 100124, China
Regulation Mechanism Of Biomolecule Interaction Behaviors On The Superlubricity Of Hydrophilic Polymer Coatings, Caixia Zhang, Junmin Chen, Mengmeng Liu, Yuhong Liu, Zhifeng Liu, Hongyan Chu, Qiang Cheng, Jianhua Wang
Friction
Hydrophilic polymer coatings can improve the surface characteristics of artificial implants. However, because they are used in vivo, they inevitably come into contact with biomolecules that affect their interfacial tribological properties. In this paper, the friction behaviors of poly(vinylphosphonic acid) (PVPA)-modified Ti6Al4V and polytetrafluorethylene balls were analyzed using albumin, globulin, aggrecan, and hyaluronic acid as lubricants. The interaction properties and dynamic adsorption characteristics of the biomolecules and PVPA molecules were explored by a quartz crystal microbalance to identify the cause of the friction difference. It was found that protein molecules disturbed the superlubricity of the PVPA-phosphate-buffered saline system because of …
A Microfluidic Bleeding Model To Investigate The Effects Of Blood Flow Shear On Microvascular Hemostasis,
2022
State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
A Microfluidic Bleeding Model To Investigate The Effects Of Blood Flow Shear On Microvascular Hemostasis, Xiangyu Hu, Haosheng Chen, Jiang Li, Kuilin Meng, Yuming Wang, Yongjian Li
Friction
Hemorrhage is the phenomenon of blood loss caused by vascular trauma or other pathological reasons, which is life-threatening in severe cases. Because microhemorrhage is difficult to visually monitor and pre-treat in vivo, it is necessary to establish in vitro prediction methods to study the hemostasis mechanism in different physiological environments. In this study, a microfluidic bleeding model was developed to investigate the effect of blood flow shear on microvascular hemostasis. The results indicated that the regulation of blood shear rate on platelet aggregation affected the growth and morphology of hemostatic thrombus, and finally regulated the process of hemostasis. This in …
Robust And Conductive Hydrogel Based On Mussel Adhesive Chemistry For Remote Monitoring Of Body Signals,
2022
State Key Laboratory of Heavy Oil Processing, Beijing Key Laboratory of Biogas Upgrading Utilization, Harvard SEAS- CUPB Joint Laboratory on Petroleum Science, China University of Petroleum, Beijing 102249, China
Robust And Conductive Hydrogel Based On Mussel Adhesive Chemistry For Remote Monitoring Of Body Signals, Weijun Li, Hao Liu, Yuanyuan Mi, Miaoran Zhang, Jinmiao Shi, Ming Zhao, Melvin A. Ramos, Travis Shihao Hu, Jianxiong Li, Meng Xu, Quan Xu
Friction
There is a high demand for hydrogels with multifunctional performance (a combination of adhesive, mechanical, and electrical properties) in biological, tissue engineering, robotics, and smart device applications. However, a majority of existing hydrogels are relatively rigid and brittle, with limited stretchability; this hinders their application in the emerging field of flexible devices. In this study, cheap and abundant potato residues were used with polyacrylamide (PAM) to fabricate a multifunctional hydrogel, and chitosan was used for the design of a three-dimentional (3D) network-structured hydrogel. The as-prepared hydrogels exhibited excellent stretchability, with an extension exceeding 900% and a recovery degree of over …
Investigation Of Role Of Cartilage Surface Polymer Brush Border In Lubrication Of Biological Joints,
2022
Department of Infrastructure Engineering, The University of Melbourne, Victoria 3010, Australia
Investigation Of Role Of Cartilage Surface Polymer Brush Border In Lubrication Of Biological Joints, Jinjing Liao, David W. Smith, Saeed Miramini, Bruce S. Gardiner, Lihai Zhang
Friction
Although experimental evidence has suggested that the polymer brush border (PBB) on the cartilage surface is important in regulating fluid permeability in the contact gap, the current theoretical understanding of joint lubrication is still limited. To address this research gap, a multiscale cartilage contact model that includes PBB, in particular its effect on the fluid permeability of the contact gap, is developed in this study. Microscale modeling is employed to estimate the permeability of the contact gap. This permeability is classified into two categories: For a gap size > 1 μm, the flow resistance is assumed to be dominated by the …
Robust Low Friction Performance Of Graphene Sheets Embedded Carbon Films Coated Orthodontic Stainless Steel Archwires,
2022
Institute of Nanosurface Science and Engineering (INSE), Guangdong Provincial Key Laboratory of Micro/Nano Optomechatronics Engineering, Shenzhen University, Shenzhen 518060, China
Robust Low Friction Performance Of Graphene Sheets Embedded Carbon Films Coated Orthodontic Stainless Steel Archwires, Zonglin Pan, Qinzhao Zhou, Pengfei Wang, Dongfeng Diao
Friction
Reducing the friction force between the commercial archwire and bracket during the orthodontic treatment in general dental practice has attracted worldwide interest. An investigation on the friction and wear behaviors of the uncoated and carbon film coated stainless steel archwires running against stainless steel brackets was systematically conducted. The carbon films were prepared at substrate bias voltages from +5 to +50 V using an electron cyclotron resonance plasma sputtering system. With increasing substrate bias voltage, local microstructures of the carbon films evolved from amorphous carbon to graphene nanocrystallites. Both static and stable friction coefficients of the archwire-bracket contacts sliding in …
Tribological Interactions Of 3d Printed Polyurethane And Polyamide With Water-Responsive Skin Model,
2022
Department of Mechanical Engineering, University of Nevada, RenoNV 89557, USA
Tribological Interactions Of 3d Printed Polyurethane And Polyamide With Water-Responsive Skin Model, Ashish K. Kasar, Ashton Chan, Victor Shamanaev, Pradeep L. Menezes
Friction
3D printing in the textile and fashion industry is a new emerging technology. Applications of 3D printing for designing clothes and other wearable accessories require tribological and biological understanding of 3D printing plastics against the complex human skin to mitigate skin-friction related ailments such as calluses and blisters. This study provides tribological insight in search of an optimal 3D printable material that has minimal friction against the skin. Two low friction 3D printable materials, thermoplastic polyurethane (TPU) and polyamide (TPA) were chosen and tribological testing was carried out against a water responsive skin model. The skin model was synthesized using …
Influence Of Two Polyphenols On The Structure And Lubrication Of Salivary Pellicle: An,
2022
Tribology Research Institute, Key Laboratory of Advanced Technologies of Materials, Ministry of Education, Southwest Jiaotong University, Chengdu 610031, China
Influence Of Two Polyphenols On The Structure And Lubrication Of Salivary Pellicle: An, Lei Lei, Yue Tang, Jing Zheng, Genlei Ma, Zhongrong Zhou
Friction
This study investigated the influence of two polyphenols on the structure and lubrication of the salivary pellicle, aiming to extend the understanding of astringency mechanisms. The salivary pellicle was prepared by the adsorption of human whole saliva on the enamel substrate. Low-astringency catechin and high-astringency tannic acid were used as astringents. The changes induced by the two polyphenols in the structure and lubrication of the salivary pellicle were examined using quartz crystal microbalance with dissipation (QCM-D) and nano- indentation/scratch technique. The salivary pellicle suffers from changes in structure and physical properties owing to protein dehydration and protein-polyphenol complexation when encountering …
An Exploration Of Frictional And Vibrational Behaviors Of Textured Deep Groove Ball Bearing In The Vicinity Of Requisite Minimum Load,
2021
Center for Biomedical Engineering, Indian Institute of Technology Delhi, New Delhi 110016, India;Department of Biomedical Engineering, College of Engineering, Osmania University, Telangana 500007, India
An Exploration Of Frictional And Vibrational Behaviors Of Textured Deep Groove Ball Bearing In The Vicinity Of Requisite Minimum Load, K. E. Ch. Vidyasagar, R. K. Pandey, Dinesh Kalyanasundaram
Friction
In case of lightly loaded radial ball bearings, failure mechanisms other than fatigue such as smearing of raceways due to increased frictional torque and vibrations often prevail. Hence, attempts have been made herein for reducing the frictional torque and minimizing the vibrations of a radial deep groove ball bearing employing surface textures at the inner race. Nanosecond pulsed laser was used to create texture (involving micro-dimples having different dimple area density) on the inner race of test bearings. Using an in-house developed test rig, frictional torque and vibrational parameters were measured at different speeds and light loads (i.e. in vicinity …
