1
|
Sun T, Gao E, Jia X, Bian J, Wang Z, Ma M, Zheng Q, Xu Z. Robust structural superlubricity under gigapascal pressures. Nat Commun 2024; 15:5952. [PMID: 39009569 PMCID: PMC11251065 DOI: 10.1038/s41467-024-49914-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Accepted: 06/17/2024] [Indexed: 07/17/2024] Open
Abstract
Structural superlubricity (SSL) is a state of contact with no wear and ultralow friction. SSL has been characterized at contact with van der Waals (vdW) layered materials, while its stability under extreme loading conditions has not been assessed. By designing both self-mated and non-self-mated vdW contacts with materials chosen for their high strengths, we report outstanding robustness of SSL under very high pressures in experiments. The incommensurate self-mated vdW contact between graphite interfaces can maintain the state of SSL under a pressure no lower than 9.45 GPa, and the non-self-mated vdW contact between a tungsten tip and graphite substrate remains stable up to 3.74 GPa. Beyond this critical pressure, wear is activated, signaling the breakdown of vdW contacts and SSL. This unexpectedly strong pressure-resistance and wear-free feature of SSL breaks down the picture of progressive wear. Atomistic simulations show that lattice destruction at the vdW contact by pressure-assisted bonding triggers wear through shear-induced tearing of the single-atomic layers. The correlation between the breakdown pressure and material properties shows that the bulk modulus and the first ionization energy are the most relevant factors, indicating the combined structural and electronic effects. Impressively, the breakdown pressures defined by the SSL interface could even exceed the strength of materials in contact, demonstrating the robustness of SSL. These findings offer a fundamental understanding of wear at the vdW contacts and guide the design of SSL-enabled applications.
Collapse
Affiliation(s)
- Taotao Sun
- Center for Nano and Micro Mechanics, Applied Mechanics Laboratory, Department of Engineering Mechanics, Tsinghua University, Beijing, China
- Railway Engineering Research Institute, China Academy of Railway Sciences Corporation Limited, Beijing, China
- State Key Laboratory for Track System of High-Speed Railway, China Academy of Railway Sciences Corporation Limited, Beijing, China
| | - Enlai Gao
- Department of Engineering Mechanics, School of Civil Engineering, Wuhan University, Wuhan, Hubei, China
| | - Xiangzheng Jia
- Department of Engineering Mechanics, School of Civil Engineering, Wuhan University, Wuhan, Hubei, China
| | - Jinbo Bian
- Center for Nano and Micro Mechanics, Applied Mechanics Laboratory, Department of Engineering Mechanics, Tsinghua University, Beijing, China
| | - Zhou Wang
- Center for Nano and Micro Mechanics, Applied Mechanics Laboratory, Department of Engineering Mechanics, Tsinghua University, Beijing, China
| | - Ming Ma
- Center for Nano and Micro Mechanics, Applied Mechanics Laboratory, Department of Engineering Mechanics, Tsinghua University, Beijing, China
| | - Quanshui Zheng
- Center for Nano and Micro Mechanics, Applied Mechanics Laboratory, Department of Engineering Mechanics, Tsinghua University, Beijing, China.
- Center of Double Helix, Institute of Materials Research, Shenzhen International Graduate School, Tsinghua University, Shenzhen, China.
- Institute of Superlubricity Technology, Research Institute of Tsinghua University in Shenzhen, Shenzhen, China.
| | - Zhiping Xu
- Center for Nano and Micro Mechanics, Applied Mechanics Laboratory, Department of Engineering Mechanics, Tsinghua University, Beijing, China.
| |
Collapse
|
2
|
Long Y, Wang X, Tan W, Li B, Li J, Deng W, Li X, Guo W, Yin J. High-Temperature Superlubricity in MoS 2/Graphene van der Waals Heterostructures. NANO LETTERS 2024; 24:7572-7577. [PMID: 38860969 DOI: 10.1021/acs.nanolett.4c00542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2024]
Abstract
Achieving high-temperature superlubricity is essential for modern extreme tribosystems. Solid lubrication is the sole viable alternative due to the degradation of liquid ones but currently suffers from notable wear, instability, and high friction coefficient. Here, we report robust superlubricity in MoS2/graphene van der Waals heterostructures at high temperatures up to ∼850 K, achieved through localized heating to enable reliable friction testing. The ultralow friction of the MoS2/graphene heterostructure is found to be notably further reduced at elevated temperature and dominantly contributed by the MoS2 edge. The observation can be well described by a multi-contact model, wherein the thermally activated rupture of edge-contacts facilitates the sliding. Our results should be applicable to other van der Waals heterostructures and shed light on their applications for superlubricity at elevated temperature.
Collapse
Affiliation(s)
- Yuyang Long
- State Key Laboratory of Mechanics and Control for Aerospace Structures, Key Laboratory for Intelligent Nano Materials and Devices of the Ministry of Education, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, People's Republic of China
| | - Xiao Wang
- State Key Laboratory of Mechanics and Control for Aerospace Structures, Key Laboratory for Intelligent Nano Materials and Devices of the Ministry of Education, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, People's Republic of China
| | - Wang Tan
- State Key Laboratory of Mechanics and Control for Aerospace Structures, Key Laboratory for Intelligent Nano Materials and Devices of the Ministry of Education, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, People's Republic of China
| | - Baowen Li
- State Key Laboratory of Mechanics and Control for Aerospace Structures, Key Laboratory for Intelligent Nano Materials and Devices of the Ministry of Education, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, People's Republic of China
| | - Jidong Li
- Institute for Frontier Science, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, People's Republic of China
| | - Wei Deng
- Institute for Frontier Science, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, People's Republic of China
| | - Xuemei Li
- State Key Laboratory of Mechanics and Control for Aerospace Structures, Key Laboratory for Intelligent Nano Materials and Devices of the Ministry of Education, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, People's Republic of China
- College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, People's Republic of China
| | - Wanlin Guo
- State Key Laboratory of Mechanics and Control for Aerospace Structures, Key Laboratory for Intelligent Nano Materials and Devices of the Ministry of Education, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, People's Republic of China
- Institute for Frontier Science, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, People's Republic of China
| | - Jun Yin
- State Key Laboratory of Mechanics and Control for Aerospace Structures, Key Laboratory for Intelligent Nano Materials and Devices of the Ministry of Education, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, People's Republic of China
| |
Collapse
|
3
|
Yu Z, Xiao Y, Huang X, Liu C, He Y, Ma M. Edge-enhanced super microgenerator based on a two-dimensional Schottky junction. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2024; 36:375001. [PMID: 38843804 DOI: 10.1088/1361-648x/ad5507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Accepted: 06/06/2024] [Indexed: 06/18/2024]
Abstract
Super microgenerator (SMG) refers to a generator that can efficiently convert extremely weak external stimuli into electrical energy and has a small size, high power density and long lifespan, offer ground-breaking solutions for powering wearable devices, wireless distributed sensors and implanted medical equipment. However, the friction and wear between the interfaces of ordinary microgenerator results in an extremely low lifespan. Here, we present a prototype of SMGs based on a 2D-2D (graphite-MoS2) Schottky contact in the state of structural superlubricity (no wear and nearly zero friction between two contacted solid surfaces). What is even more interesting is when the graphite flake is slid from the bulk to the edge of MoS2, the output current will enhance from 31 to 56 A m-2. Through the I-V curve measurement, we found that the conductive channel across the junction can be activated and further enhanced at the edge of MoS2compare to bulk, which provide the explanation for the above-mentioned edge enhancement of power generation. Above results provide the design principles of high-performance SMGs based on 2D-2D Schottky junctions.
Collapse
Affiliation(s)
- Zhaokuan Yu
- Department of Physics, Zhejiang University, Hangzhou 310027, People's Republic of China
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, People's Republic of China
| | - Yangfan Xiao
- School of Mechanical Engineering, Southwest Jiaotong University, Chengdu 610031, People's Republic of China
| | - Xuanyu Huang
- Institute of Superlubricity Technology, Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057, People's Republic of China
| | - Chenleyang Liu
- School of Mechanical Engineering, Southwest Jiaotong University, Chengdu 610031, People's Republic of China
| | - Yuqing He
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, People's Republic of China
- State Key Laboratory of Tribology in Advanced Equipment and Department of Mechanical Engineering, Tsinghua University, Beijing 100084, People's Republic of China
| | - Ming Ma
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, People's Republic of China
- Institute of Superlubricity Technology, Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057, People's Republic of China
- State Key Laboratory of Tribology in Advanced Equipment and Department of Mechanical Engineering, Tsinghua University, Beijing 100084, People's Republic of China
| |
Collapse
|
4
|
Wu Z, Li X, Peng D, Zheng Q. Positive-Negative Tunable Coefficients of Friction in Superlubric Contacts. PHYSICAL REVIEW LETTERS 2024; 132:156201. [PMID: 38683007 DOI: 10.1103/physrevlett.132.156201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Accepted: 03/13/2024] [Indexed: 05/01/2024]
Abstract
In conventional systems, the coefficient of friction (COF) is typically positive, signifying a direct relationship between frictional and normal forces. Contrary to this, we observe that the load dependence of friction exhibits a unique bell-shaped curve when studying the frictional properties between graphite and α-Al_{2}O_{3} surfaces. As the applied normal force increases, the friction initially rises and then decreases. Finite element simulations reveal this behavior is due to edge detachment at the graphite/α-Al_{2}O_{3} interface as the normal force approaches a critical value. Because friction in superlubric contacts predominantly arises from edges, their detachment leads to a decrease in overall friction. We empirically validate these findings by varying the radii of curvature of the tips and the thicknesses of graphite flakes. This unprecedented observation offers a new paradigm for tuning COF in superlubric applications, enabling transitions from positive to negative values.
Collapse
Affiliation(s)
- Zhanghui Wu
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China
- Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
| | - Xuanhe Li
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Deli Peng
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China
- Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
- Institute of Superlubricity Technology, Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057, China
| | - Quanshui Zheng
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China
- Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
- Institute of Superlubricity Technology, Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057, China
- Center of Double Helix, Tsinghua Shenzhen International Graduate School, Shenzhen 518057, China
| |
Collapse
|
5
|
Gao X, Cheng Y, Shi M, Chen H, Wu L, Wang T. Design of Superlubricity System Using Si 3N 4/Polyimide as the Friction Pair and Nematic Liquid Crystals as the Lubricant. Polymers (Basel) 2023; 15:3693. [PMID: 37765546 PMCID: PMC10535595 DOI: 10.3390/polym15183693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 08/23/2023] [Accepted: 09/05/2023] [Indexed: 09/29/2023] Open
Abstract
Polyimide (PI) is a high-performance engineering plastic used as a bearing material. A superlubricity system using Si3N4/PI as the friction pair and nematic liquid crystals (LCs) as the lubricant was designed. The superlubricity performance was studied by simulating the start-stop condition of the machine, and it was found that the superlubricity system had good reproducibility and stability. In the superlubricity system, friction aligned with the PI molecules, and this alignment was less relevant compared to which substance was rubbing on the PI. Oriented PI molecules induced LC molecule alignment when the pretilt angle was very small, and the LC molecules were almost parallel to the PI molecules due to the one-dimensional ordered arrangement of LC molecules and low viscosity, which is conducive to the occurrence of the superlubricity phenomenon.
Collapse
Affiliation(s)
- Xinlei Gao
- School of Materials Science and Engineering, Hubei University, Wuhan 430062, China
| | - Yuwei Cheng
- School of Chemical and Environmental Engineering, Wuhan Polytechnic University, Wuhan 430023, China
| | - Miaomiao Shi
- School of Chemical and Environmental Engineering, Wuhan Polytechnic University, Wuhan 430023, China
| | - Hao Chen
- School of Chemical and Environmental Engineering, Wuhan Polytechnic University, Wuhan 430023, China
| | - Li Wu
- School of Chemistry and Environmental Engineering, Wuhan Institute of Technology, Wuhan 430074, China
| | - Tingting Wang
- School of Chemical and Environmental Engineering, Wuhan Polytechnic University, Wuhan 430023, China
| |
Collapse
|
6
|
Dong R, Lunghi A, Sanvito S. Stiffness and Atomic-Scale Friction in Superlubricant MoS 2 Bilayers. J Phys Chem Lett 2023:6086-6091. [PMID: 37358918 DOI: 10.1021/acs.jpclett.3c01066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/28/2023]
Abstract
Molecular dynamics simulations, performed with chemically accurate ab initio machine-learning force fields, are used to demonstrate that layer stiffness has profound effects on the superlubricant state of two-dimensional van der Waals heterostructures. We engineer bilayers of different rigidity but identical interlayer sliding energy surface and show that a 2-fold increase in the intralayer stiffness reduces the friction by a factor of ∼6. Two sliding regimes as a function of the sliding velocity are found. At a low velocity, the heat generated by the motion is efficiently exchanged between the layers and the friction is independent of the layer order. In contrast, at a high velocity, the friction heat flux cannot be exchanged fast enough and a buildup of significant temperature gradients between the layers is observed. In this situation, the temperature profile depends on whether the slider is softer than the substrate.
Collapse
Affiliation(s)
- Rui Dong
- School of Physics, AMBER and CRANN Institute, Trinity College, Dublin 2, Ireland
| | - Alessandro Lunghi
- School of Physics, AMBER and CRANN Institute, Trinity College, Dublin 2, Ireland
| | - Stefano Sanvito
- School of Physics, AMBER and CRANN Institute, Trinity College, Dublin 2, Ireland
| |
Collapse
|
7
|
Huang X, Li T, Wang J, Xia K, Tan Z, Peng D, Xiang X, Liu B, Ma M, Zheng Q. Robust microscale structural superlubricity between graphite and nanostructured surface. Nat Commun 2023; 14:2931. [PMID: 37217500 DOI: 10.1038/s41467-023-38680-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 05/09/2023] [Indexed: 05/24/2023] Open
Abstract
Structural superlubricity is a state of nearly zero friction and no wear between two contacted solid surfaces. However, such state has a certain probability of failure due to the edge defects of graphite flake. Here, we achieve robust structural superlubricity state between microscale graphite flakes and nanostructured silicon surfaces under ambient condition. We find that the friction is always less than 1 μN, the differential friction coefficient is on the order of 10-4, without observable wear. This is attributed to the edge warping of graphite flake on the nanostructured surface under concentrated force, which eliminate the edge interaction between the graphite flake and the substrate. This study not only challenges the traditional understanding in tribology and structural superlubricity that rougher surfaces lead to higher friction and lead to wear, thereby reducing roughness requirements, but also demonstrates that a graphite flake with a single crystal surface that does not come into edge contact with the substrate can consistently achieve robust structural superlubricity state with any non-van der Waals material in atmospheric conditions. Additionally, the study provides a general surface modification method that enables the widespread application of structural superlubricity technology in atmospheric environments.
Collapse
Affiliation(s)
- Xuanyu Huang
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing, 100084, China
- Department of Mechanical Engineering, Tsinghua University, Beijing, 100084, China
- State Key Laboratory of Tribology in Advanced Equipment (SKLT), Tsinghua University, Beijing, 10084, China
| | - Tengfei Li
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing, 100084, China
- Department of Engineering Mechanics, Tsinghua University, Beijing, 100084, China
| | - Jin Wang
- International School for Advanced Studies, Trieste, 34136, Italy
| | - Kai Xia
- Institute of Superlubricity Technology, Research Institute of Tsinghua University in Shenzhen, Shenzhen, 518057, China
| | - Zipei Tan
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing, 100084, China
- Department of Engineering Mechanics, Tsinghua University, Beijing, 100084, China
| | - Deli Peng
- Institute of Superlubricity Technology, Research Institute of Tsinghua University in Shenzhen, Shenzhen, 518057, China
| | - Xiaojian Xiang
- Institute of Superlubricity Technology, Research Institute of Tsinghua University in Shenzhen, Shenzhen, 518057, China
| | - Bin Liu
- Department of Engineering Mechanics, Tsinghua University, Beijing, 100084, China
| | - Ming Ma
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing, 100084, China.
- Department of Mechanical Engineering, Tsinghua University, Beijing, 100084, China.
- State Key Laboratory of Tribology in Advanced Equipment (SKLT), Tsinghua University, Beijing, 10084, China.
- Institute of Superlubricity Technology, Research Institute of Tsinghua University in Shenzhen, Shenzhen, 518057, China.
| | - Quanshui Zheng
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing, 100084, China.
- Department of Mechanical Engineering, Tsinghua University, Beijing, 100084, China.
- State Key Laboratory of Tribology in Advanced Equipment (SKLT), Tsinghua University, Beijing, 10084, China.
- Department of Engineering Mechanics, Tsinghua University, Beijing, 100084, China.
- Institute of Superlubricity Technology, Research Institute of Tsinghua University in Shenzhen, Shenzhen, 518057, China.
| |
Collapse
|
8
|
Reproducibility in the fabrication and physics of moiré materials. Nature 2022; 602:41-50. [PMID: 35110759 DOI: 10.1038/s41586-021-04173-z] [Citation(s) in RCA: 52] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 10/21/2021] [Indexed: 11/08/2022]
Abstract
Overlaying two atomic layers with a slight lattice mismatch or at a small rotation angle creates a moiré superlattice, which has properties that are markedly modified from (and at times entirely absent in) the 'parent' materials. Such moiré materials have progressed the study and engineering of strongly correlated phenomena and topological systems in reduced dimensions. The fundamental understanding of the electronic phases, such as superconductivity, requires a precise control of the challenging fabrication process, involving the rotational alignment of two atomically thin layers with an angular precision below 0.1 degrees. Here we review the essential properties of moiré materials and discuss their fabrication and physics from a reproducibility perspective.
Collapse
|
9
|
Peng D, Wang J, Jiang H, Zhao S, Wu Z, Tian K, Ma M, Zheng Q. 100 km wear-free sliding achieved by microscale superlubric graphite/DLC heterojunctions under ambient conditions. Natl Sci Rev 2022; 9:nwab109. [PMID: 35070329 PMCID: PMC8776547 DOI: 10.1093/nsr/nwab109] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 06/05/2021] [Accepted: 06/17/2021] [Indexed: 01/09/2023] Open
Abstract
Wear-free sliding between two contacted solid surfaces is the ultimate goal in the effort to extend the lifetime of mechanical devices, especially when it comes to inventing new types of micro-electromechanical systems where wear is often a major obstacle. Here we report experimental observations of wear-free sliding for a micrometer-sized graphite flake on a diamond-like-carbon (DLC) surface under ambient conditions with speeds up to 2.5 m/s, and over a distance of 100 km. The coefficient of friction (COF) between the microscale graphite flake, a van der Waals (vdW) layered material and DLC, a non-vdW-layered material, is measured to be of the order of \documentclass[12pt]{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{upgreek}
\usepackage{mathrsfs}
\setlength{\oddsidemargin}{-69pt}
\begin{document}
}{}${10^{ - 3}}$\end{document}, which belongs to the superlubric regime. Such ultra-low COFs are also demonstrated for a microscale graphite flake sliding on six other kinds of non-vdW-layered materials with sub-nanometer roughness. With a synergistic analysis approach, we reveal the underlying mechanism to be the combination of interfacial vdW interaction, atomic-smooth interfaces and the low normal stiffness of the graphite flake. These features guarantee a persistent full contact of the interface with weak interaction, which contributes to the ultra-low COFs. Together with the extremely high in-plane strength of graphene, wear-free sliding is achieved. Our results broaden the scope of superlubricity and promote its wider application in the future.
Collapse
Affiliation(s)
- Deli Peng
- Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
| | - Jin Wang
- Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
| | - Haiyang Jiang
- Institute of Superlubricity Technology, Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057, China
| | - Shuji Zhao
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China
| | - Zhanghui Wu
- Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
| | - Kaiwen Tian
- Institute of Superlubricity Technology, Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057, China
| | - Ming Ma
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China
| | - Quanshui Zheng
- Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
| |
Collapse
|
10
|
Yuan J, Yang R, Zhang G. Structural superlubricity in 2D van der Waals heterojunctions. NANOTECHNOLOGY 2021; 33:102002. [PMID: 34229304 DOI: 10.1088/1361-6528/ac1197] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 07/05/2021] [Indexed: 06/13/2023]
Abstract
Structural superlubricity is a fundamentally important research topic in the area of tribology. Van der Waals heterojunctions of 2D materials are an ideal system for achieving structural superlubricity and possessing potentially a wide range of applications in the future due to their ultra-flat and incommensurate crystal interfaces. Here we briefly introduce the origin and mechanism of structural superlubricity and summarize the representative experimental results, in which the coefficient of friction has achieved the order of 10-5. Furthermore, we analyze the factors affecting structural superlubricity of 2D materials, including dynamic reconstruction of interfaces, edge effects, interfacial adsorption, etc, and give a perspective on how to realize the macroscopic expansion and where it can be applied in practice.
Collapse
Affiliation(s)
- Jiahao Yuan
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Rong Yang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, People's Republic of China
| | - Guangyu Zhang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, People's Republic of China
| |
Collapse
|
11
|
Xu Y, Li H, Zhang X, Liu W, Zhang Z, Qin S, Liu J. Single pixel wide gamut dynamic color modulation based on a graphene micromechanical system. OPTICS EXPRESS 2021; 29:32491-32504. [PMID: 34615318 DOI: 10.1364/oe.434381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 09/13/2021] [Indexed: 06/13/2023]
Abstract
Dynamic color modulation in the composite structure of a graphene microelectromechanical system (MEMS)-photonic crystal microcavity is investigated in this work. The designed photonic crystal microcavity has three resonant standing wave modes corresponding to the three primary colors of red (R), green (G) and blue (B), forming strong localization of light in three modes at different positions of the microcavity. Once graphene is added, it can govern the transmittance of three modes. When graphene is located in the antinode of the standing wave, it has strong light absorption and therefore the structure's transmittance is lower, and when graphene is located in the node of the standing wave, it has weak light absorption and therefore the structure's transmittance is higher. Therefore, the graphene absorption of different colors of light can be regulated dynamically by applying voltages to tune the equilibrium position of the graphene MEMS in the microcavity, consequently realizing the output of vivid monochromatic light or multiple mixed colors of light within a single pixel, thus greatly improving the resolution. Our work provides a route to dynamic color modulation with graphene and provides guidance for the design and manufacture of high resolution, fast modulation and wide color gamut interferometric modulator displays.
Collapse
|
12
|
Ouyang W, Hod O, Urbakh M. Registry-Dependent Peeling of Layered Material Interfaces: The Case of Graphene Nanoribbons on Hexagonal Boron Nitride. ACS APPLIED MATERIALS & INTERFACES 2021; 13:43533-43539. [PMID: 34486375 PMCID: PMC8488940 DOI: 10.1021/acsami.1c09529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Accepted: 08/23/2021] [Indexed: 06/13/2023]
Abstract
Peeling of layered materials from supporting substrates, which is central for exfoliation and transfer processes, is found to be dominated by lattice commensurability effects in both low and high velocity limits. For a graphene nanoribbon atop a hexagonal boron nitride surface, the microscopic peeling behavior ranges from stick-slip, through smooth-sliding, to pure peeling regimes, depending on the relative orientation of the contacting surfaces and the peeling angle. The underlying mechanisms stem from the intimate relation between interfacial registry, interlayer interactions, and friction. This, in turn, allows for devising simple models for extracting the interfacial adhesion energy from the peeling force traces.
Collapse
Affiliation(s)
- Wengen Ouyang
- Department
of Engineering Mechanics, School of Civil Engineering, Wuhan University, Wuhan, Hubei 430072, China
| | - Oded Hod
- Department
of Physical Chemistry, School of Chemistry, The Raymond and Beverly
Sackler Faculty of Exact Sciences and The Sackler Center for Computational
Molecular and Materials Science, Tel Aviv
University, Tel Aviv 6997801, Israel
| | - Michael Urbakh
- Department
of Physical Chemistry, School of Chemistry, The Raymond and Beverly
Sackler Faculty of Exact Sciences and The Sackler Center for Computational
Molecular and Materials Science, Tel Aviv
University, Tel Aviv 6997801, Israel
| |
Collapse
|
13
|
Interfacial Friction Anisotropy in Few-Layer Van der Waals Crystals. MATERIALS 2021; 14:ma14164717. [PMID: 34443239 PMCID: PMC8401590 DOI: 10.3390/ma14164717] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Revised: 07/30/2021] [Accepted: 08/13/2021] [Indexed: 01/27/2023]
Abstract
Friction anisotropy is one of the important friction behaviors for two-dimensional (2D) van der Waals (vdW) crystals. The effects of normal pressure and thickness on the interfacial friction anisotropy in few-layer graphene, h-BN, and MoSe2 under constant normal force mode have been extensively investigated by first-principle calculations. The increase of normal pressure and layer number enhances the interfacial friction anisotropy for graphene and h-BN but weakens that for MoSe2. Such significant deviations in the interfacial friction anisotropy of few-layer graphene, h-BN and MoSe2 can be mainly attributed to the opposite contributions of electron kinetic energies and electrostatic energies to the sliding energy barriers and different interlayer charge exchanges. Our results deepen the understanding of the influence of external loading and thickness on the friction properties of 2D vdW crystals.
Collapse
|
14
|
Huang X, Xiang X, Nie J, Peng D, Yang F, Wu Z, Jiang H, Xu Z, Zheng Q. Microscale Schottky superlubric generator with high direct-current density and ultralong life. Nat Commun 2021; 12:2268. [PMID: 33859180 PMCID: PMC8050059 DOI: 10.1038/s41467-021-22371-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 02/26/2021] [Indexed: 02/02/2023] Open
Abstract
Miniaturized or microscale generators that can effectively convert weak and random mechanical energy into electricity have significant potential to provide solutions for the power supply problem of distributed devices. However, owing to the common occurrence of friction and wear, all such generators developed so far have failed to simultaneously achieve sufficiently high current density and sufficiently long lifetime, which are crucial for real-world applications. To address this issue, we invent a microscale Schottky superlubric generator (S-SLG), such that the sliding contact between microsized graphite flakes and n-type silicon is in a structural superlubric state (an ultra-low friction and wearless state). The S-SLG not only generates high current (~210 Am-2) and power (~7 Wm-2) densities, but also achieves a long lifetime of at least 5,000 cycles, while maintaining stable high electrical current density (~119 Am-2). No current decay and wear are observed during the experiment, indicating that the actual persistence of the S-SLG is enduring or virtually unlimited. By excluding the mechanism of friction-induced excitation in the S-SLG, we further demonstrate an electronic drift process during relative sliding using a quasi-static semiconductor finite element simulation. Our work may guide and accelerate the future use of S-SLGs in real-world applications.
Collapse
Affiliation(s)
- Xuanyu Huang
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing, 100084, China
- Department of Mechanical Engineering, Tsinghua University, Beijing, 100084, China
- State Key Lab of Tribology, Tsinghua University, Beijing, 10084, China
| | - Xiaojian Xiang
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing, 100084, China
- Department of Engineering Mechanics, Tsinghua University, Beijing, 100084, China
- Institute of Superlubricity Technology, Research Institute of Tsinghua University in Shenzhen, Shenzhen, 518057, China
| | - Jinhui Nie
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing, 100084, China
- Department of Engineering Mechanics, Tsinghua University, Beijing, 100084, China
- Institute of Superlubricity Technology, Research Institute of Tsinghua University in Shenzhen, Shenzhen, 518057, China
| | - Deli Peng
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing, 100084, China
- Department of Engineering Mechanics, Tsinghua University, Beijing, 100084, China
| | - Fuwei Yang
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing, 100084, China
- Department of Engineering Mechanics, Tsinghua University, Beijing, 100084, China
| | - Zhanghui Wu
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing, 100084, China
- Department of Engineering Mechanics, Tsinghua University, Beijing, 100084, China
| | - Haiyang Jiang
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing, 100084, China
- Institute of Superlubricity Technology, Research Institute of Tsinghua University in Shenzhen, Shenzhen, 518057, China
| | - Zhiping Xu
- Department of Engineering Mechanics, Tsinghua University, Beijing, 100084, China
| | - Quanshui Zheng
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing, 100084, China.
- Department of Mechanical Engineering, Tsinghua University, Beijing, 100084, China.
- State Key Lab of Tribology, Tsinghua University, Beijing, 10084, China.
- Department of Engineering Mechanics, Tsinghua University, Beijing, 100084, China.
- Institute of Superlubricity Technology, Research Institute of Tsinghua University in Shenzhen, Shenzhen, 518057, China.
| |
Collapse
|
15
|
Wei N, Li Z, Li ZH, Zhang C, Wang C, Zhao J, Cai K. A heat and force locating sensor with nanoscale precision: a knitted graphene sheet. NANOSCALE 2021; 13:5826-5833. [PMID: 33710203 DOI: 10.1039/d0nr08829c] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Fast and accurately locating the heating or force bearing points is essential to the maintenance and diagnosis of nano/micro-electromechanical systems. Here, a knitted graphene sheet (KGS), prepared by knitting graphene nanoribbons, is proposed as a heat or force sensor to locate the spot with nanoscale precision under thermal or mechanical loadings. The heat flux transport among the ribbons in the KGS is more difficult than in the ribbon due to the weaker van der Waals interactions among ribbons, so the heat energy can be restricted in the directly loaded ribbons over a period of time. Molecular dynamics results demonstrate that the KGS can efficiently locate and evaluate the spots and sizes of heat/force sources with high accuracy dependent on the width of the ribbons in the KGS. Our research provides a new detection approach and sheds light on designing and assembling KGS-based nanosensors for locating thermal and mechanical loads.
Collapse
Affiliation(s)
- Ning Wei
- Jiangsu Key Laboratory of Advanced Food Manufacturing Equipment and Technology, Jiangnan University, 214122 Wuxi, China.
| | | | | | | | | | | | | |
Collapse
|
16
|
Vanossi A, Bechinger C, Urbakh M. Structural lubricity in soft and hard matter systems. Nat Commun 2020; 11:4657. [PMID: 32938930 PMCID: PMC7495432 DOI: 10.1038/s41467-020-18429-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 08/17/2020] [Indexed: 11/09/2022] Open
Abstract
Over the recent decades there has been tremendous progress in understanding and controlling friction between surfaces in relative motion. However the complex nature of the involved processes has forced most of this work to be of rather empirical nature. Two very distinctive physical systems, hard two-dimensional layered materials and soft microscopic systems, such as optically or topographically trapped colloids, have recently opened novel rationally designed lines of research in the field of tribology, leading to a number of new discoveries. Here, we provide an overview of these emerging directions of research, and discuss how the interplay between hard and soft matter promotes our understanding of frictional phenomena. Structural lubricity is one of the most interesting concepts in modern tribology, which promises to achieve ultra-low friction over a wide range of length-scales. Here the authors highlight novel research lines in this area achievable by combining theoretical and experimental efforts on hard two-dimensional materials and soft colloidal and cold ion systems.
Collapse
Affiliation(s)
- Andrea Vanossi
- CNR-IOM Democritos National Simulation Center, Trieste, Italy. .,International School for Advanced Studies (SISSA), Trieste, Italy.
| | | | - Michael Urbakh
- School of Chemistry and The Sackler Center for Computational Molecular and Materials Science, Tel Aviv University, Tel Aviv, 6997801, Israel.
| |
Collapse
|
17
|
Li P, Ju P, Ji L, Li H, Liu X, Chen L, Zhou H, Chen J. Toward Robust Macroscale Superlubricity on Engineering Steel Substrate. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e2002039. [PMID: 32715515 DOI: 10.1002/adma.202002039] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 06/12/2020] [Indexed: 06/11/2023]
Abstract
"Structural superlubricity" is an important fundamental phenomenon in modern tribology that is expected to greatly diminish friction in mechanical engineering, but now is limited to achieve only at nanoscale and microscale in experiment. A novel principle for broadening the structural superlubricating state based on numberless micro-contact into macroscale superlubricity is demonstrated. The topography of micro-asperities on engineering steel substrates is elaborately constructed to divide the macroscale surface contact into microscale point contacts. Then at each contact point, special measures such as pre-running-in period and coating heterogeneous covalent/ionic or ionic/ionic nanocomposite of 2D materials are devised to manipulate the interfacial ordered layer-by-layer state, weak chemical interaction, and incommensurate configuration, thereby satisfying the prerequisites responsible for structural superlubricity. Finally, the robust superlubricating states on engineering steel-steel macroscale contact pairs are achieved with significantly reduced friction coefficient in 10-3 magnitude, extra-long antiwear life (more than 1.0 × 106 laps), and good universality to wide range of materials and loads, which can be of significance for the industrialization of "structural superlubricity."
Collapse
Affiliation(s)
- Panpan Li
- Key Laboratory of Science and Technology on Wear and Protection of Materials, State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Pengfei Ju
- Shanghai Aerospace Equipment Manufacture, Shanghai, 200245, China
| | - Li Ji
- Key Laboratory of Science and Technology on Wear and Protection of Materials, State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Hongxuan Li
- Key Laboratory of Science and Technology on Wear and Protection of Materials, State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xiaohong Liu
- Key Laboratory of Science and Technology on Wear and Protection of Materials, State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Lei Chen
- Key Laboratory of Science and Technology on Wear and Protection of Materials, State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Huidi Zhou
- Key Laboratory of Science and Technology on Wear and Protection of Materials, State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jianmin Chen
- Key Laboratory of Science and Technology on Wear and Protection of Materials, State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| |
Collapse
|
18
|
Abstract
Applying an increasing normal load on microscale graphite mesas, we observe two dynamic phenomena. First, the loaded mesa suddenly and laterally ejects a thin flake; second, a flake repeatedly pops out of the mesa and retracts back. The measured ejection speeds are extraordinarily high (maximum of 294 m/s), corresponding to ultrahigh accelerations (maximum of 1.1 × 1010 m/s2). These phenomena are a consequence of structural superlubricity, a state of nearly zero friction between two solid surfaces, and may motivate inventions of many superlubric devices, that was first proposed 17 years ago. The structural superlubricity (SSL), a state of near-zero friction between two contacted solid surfaces, has been attracting rapidly increasing research interest since it was realized in microscale graphite in 2012. An obvious question concerns the implications of SSL for micro- and nanoscale devices such as actuators. The simplest actuators are based on the application of a normal load; here we show that this leads to remarkable dynamical phenomena in microscale graphite mesas. Under an increasing normal load, we observe mechanical instabilities leading to dynamical states, the first where the loaded mesa suddenly ejects a thin flake and the second characterized by peculiar oscillations, during which a flake repeatedly pops out of the mesa and retracts back. The measured ejection speeds are extraordinarily high (maximum of 294 m/s), and correspond to ultrahigh accelerations (maximum of 1.1×1010 m/s2). These observations are rationalized using a simple model, which takes into account SSL of graphite contacts and sample microstructure and considers a competition between the elastic and interfacial energies that defines the dynamical phase diagram of the system. Analyzing the observed flake ejection and oscillations, we conclude that our system exhibits a high speed in SSL, a low friction coefficient of 3.6×10−6, and a high quality factor of 1.3×107 compared with what has been reported in literature. Our experimental discoveries and theoretical findings suggest a route for development of SSL-based devices such as high-frequency oscillators with ultrahigh quality factors and optomechanical switches, where retractable or oscillating mirrors are required.
Collapse
|
19
|
Dong Y, Tao Y, Feng R, Zhang Y, Duan Z, Cao H. Phonon dissipation in friction with commensurate-incommensurate transition between graphene membranes. NANOTECHNOLOGY 2020; 31:285711. [PMID: 32252042 DOI: 10.1088/1361-6528/ab86ec] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
To examine phonon transport during the friction process of commensurate-incommensurate transition, the vibrational density of states of contact surfaces is calculated based on molecular dynamics simulations. The results indicate that, compared with the static state, the relative sliding of the contact surfaces causes a blue shift in the interfacial phonon spectrum in or close to commensurate contact, whereas the contrast of the phonon spectrum in incommensurate contact is almost indiscernible. Further findings suggest that the cause of friction can be attributed to the excitation of new in-plane acoustic modes, which provide the most efficient energy dissipation channels in the friction process. In addition, when the tip and the substrate are subjected to a same biaxial compressive/tensile strain, fewer new acoustic modes are excited than in the no strain case. Thus, the friction can be controlled by applying in-plane strain even in commensurate contact. The contribution of the excited acoustic modes to friction at various frequency bands is also calculated, which provides theoretical guidance for controlling friction by adjusting excitation phonon modes.
Collapse
Affiliation(s)
- Yun Dong
- School of Mechanical and Electrical Engineering, Lanzhou University of Technology, Lanzhou 730050, People's Republic of China. School of Mechanical Engineering, Southeast University, Nanjing 211189, People's Republic of China
| | | | | | | | | | | |
Collapse
|
20
|
Song Y, Qu C, Ma M, Zheng Q. Structural Superlubricity Based on Crystalline Materials. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2020; 16:e1903018. [PMID: 31670482 DOI: 10.1002/smll.201903018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 09/06/2019] [Indexed: 06/10/2023]
Abstract
Herein, structural superlubricity, a fascinating phenomenon where the friction is ultralow due to the lateral interaction cancellation resulted from incommensurate contact crystalline surfaces, is reviewed. Various kinds of nano- and microscale materials such as 2D materials, metals, and compounds are used for the fabrication. For homogeneous frictional pairs, superlow friction forces exist in most relative orientations with incommensurate configuration. Heterojunctions bear no resemblance to homogeneous contact, since the lattice constants are naturally mismatched which leads to a robust structural superlubricity with any orientation of the two different surfaces. A discussion on the perspectives of this field is also provided to meet the existing challenges and chart the future.
Collapse
Affiliation(s)
- Yiming Song
- State Key Laboratory of Tribology, Department of Mechanical Engineering, Center for Nano and Micro Mechanics, Tsinghua University, Beijing, 100084, China
| | - Cangyu Qu
- Department of Engineering Mechanics, Center for Nano and Micro Mechanics, Tsinghua University, Beijing, 100084, China
| | - Ming Ma
- State Key Laboratory of Tribology, Department of Mechanical Engineering, Center for Nano and Micro Mechanics, Tsinghua University, Beijing, 100084, China
| | - Quanshui Zheng
- State Key Laboratory of Tribology, Department of Engineering Mechanics, Center for Nano and Micro Mechanics, Tsinghua University, Beijing, 100084, China
| |
Collapse
|
21
|
Liu B, Wang J, Zhao S, Qu C, Liu Y, Ma L, Zhang Z, Liu K, Zheng Q, Ma M. Negative friction coefficient in microscale graphite/mica layered heterojunctions. SCIENCE ADVANCES 2020; 6:eaaz6787. [PMID: 32494618 PMCID: PMC7164938 DOI: 10.1126/sciadv.aaz6787] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 01/22/2020] [Indexed: 06/11/2023]
Abstract
The friction of a solid contact typically shows a positive dependence on normal load according to classic friction laws. A few exceptions were recently observed for nanoscale single-asperity contacts. Here, we report the experimental observation of negative friction coefficient in microscale monocrystalline heterojunctions at different temperatures. The results for the interface between graphite and muscovite mica heterojunction demonstrate a robust negative friction coefficient both in loading and unloading processes. Molecular dynamics simulations reveal that the underlying mechanism is a synergetic and nontrivial redistribution of water molecules at the interface, leading to larger density and more ordered structure of the confined subnanometer-thick water film. Our results are expected to be applicable to other hydrophilic van der Waals heterojunctions.
Collapse
Affiliation(s)
- Bingtong Liu
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
- Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China
| | - Jin Wang
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China
- Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
| | - Shuji Zhao
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
- Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China
| | - Cangyu Qu
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China
- Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
| | - Yuan Liu
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
- Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China
| | - Liran Ma
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
- Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China
| | - Zhihong Zhang
- State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
| | - Kaihui Liu
- State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
| | - Quanshui Zheng
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China
- Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
| | - Ming Ma
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
- Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China
| |
Collapse
|
22
|
Zhang Z, Du Y, Huang S, Meng F, Chen L, Xie W, Chang K, Zhang C, Lu Y, Lin C, Li S, Parkin IP, Guo D. Macroscale Superlubricity Enabled by Graphene-Coated Surfaces. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2020; 7:1903239. [PMID: 32099768 PMCID: PMC7029642 DOI: 10.1002/advs.201903239] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 12/12/2019] [Indexed: 05/03/2023]
Abstract
Friction and wear remain the primary modes for energy dissipation in moving mechanical components. Superlubricity is highly desirable for energy saving and environmental benefits. Macroscale superlubricity was previously performed under special environments or on curved nanoscale surfaces. Nevertheless, macroscale superlubricity has not yet been demonstrated under ambient conditions on macroscale surfaces, except in humid air produced by purging water vapor into a tribometer chamber. In this study, a tribological system is fabricated using a graphene-coated plate (GCP), graphene-coated microsphere (GCS), and graphene-coated ball (GCB). The friction coefficient of 0.006 is achieved in air under 35 mN at a sliding speed of 0.2 mm s-1 for 1200 s in the developed GCB/GCS/GCP system. To the best of the knowledge, for the first time, macroscale superlubricity on macroscale surfaces under ambient conditions is reported. The mechanism of macroscale superlubricity is due to the combination of exfoliated graphene flakes and the swinging and sliding of the GCS, which is demonstrated by the experimental measurements, ab initio, and molecular dynamics simulations. These findings help to bridge macroscale superlubricity to real world applications, potentially dramatically contributing to energy savings and reducing the emission of carbon dioxide to the environment.
Collapse
Affiliation(s)
- Zhenyu Zhang
- Key Laboratory for Precision and Non‐Traditional Machining Technology of Ministry of EducationDalian University of TechnologyDalian116024China
| | - Yuefeng Du
- Key Laboratory for Precision and Non‐Traditional Machining Technology of Ministry of EducationDalian University of TechnologyDalian116024China
| | - Siling Huang
- Key Laboratory for Precision and Non‐Traditional Machining Technology of Ministry of EducationDalian University of TechnologyDalian116024China
| | - Fanning Meng
- Key Laboratory for Precision and Non‐Traditional Machining Technology of Ministry of EducationDalian University of TechnologyDalian116024China
| | - Leilei Chen
- Key Laboratory for Precision and Non‐Traditional Machining Technology of Ministry of EducationDalian University of TechnologyDalian116024China
| | - Wenxiang Xie
- Key Laboratory for Precision and Non‐Traditional Machining Technology of Ministry of EducationDalian University of TechnologyDalian116024China
| | - Keke Chang
- Key Laboratory of Marine Materials and Related TechnologiesNingbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo315201China
| | - Chenhui Zhang
- State Key Laboratory of TribologyDepartment of Mechanical EngineeringTsinghua UniversityBeijing100084China
| | - Yao Lu
- Department of ChemistrySchool of Biological and Chemical SciencesQueen Mary University of LondonLondonE1 4NSUK
| | - Cheng‐Te Lin
- State Key Laboratory of TribologyDepartment of Mechanical EngineeringTsinghua UniversityBeijing100084China
| | - Suzhi Li
- State Key Laboratory for Mechanical Behavior of MaterialsXi'an Jiaotong UniversityXi'an710049China
| | - Ivan P. Parkin
- Materials Chemistry Research CentreDepartment of ChemistryUniversity College London20 Gordon StreetLondonWC1H 0AJUK
| | - Dongming Guo
- Key Laboratory for Precision and Non‐Traditional Machining Technology of Ministry of EducationDalian University of TechnologyDalian116024China
| |
Collapse
|
23
|
Lin B, Ding M, Sui T, Cui Y, Yan S, Liu X. Excellent Water Lubrication Additives for Silicon Nitride To Achieve Superlubricity under Extreme Conditions. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:14861-14869. [PMID: 31663750 DOI: 10.1021/acs.langmuir.9b02337] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Superlubricity has been recognized as the future of tribology. However, it is hard to achieve superlubricity under extreme conditions such as a high load and low sliding speed on the macroscale. In this paper, a remarkable synergetic lubricating effect between nanoparticles and silicon nitride (Si3N4) is demonstrated; this effect helps water-lubricated Si3N4 achieve superlubricity under extreme conditions successfully. Different kinds of hairy silica nanoparticles were prepared, dispersed into water, and characterized using a variety of methods. The tribological properties of water-lubricated Si3N4 with nanoparticle additives were tested using a ball-on-disk tribometer under different loads and sliding speeds. The coefficient of friction and wear scar diameter were measured and analyzed. Both the nanoparticle size and surface functional groups have a significant influence on the tribological properties of water-lubricated Si3N4. Amino-modified silica nanoparticles reduce the friction coefficient of water-lubricated Si3N4 by 82.9% under 60 N, compared with that achieved using deionized water, and induce superlubricity after the running-in process. Silica nanoparticles effectively form a homogenous film with silica gel on the worn surface under a high load and thus reduce the wear and maintain the superlubricity under extreme conditions.
Collapse
Affiliation(s)
| | | | | | | | | | - Xibei Liu
- Chemicals, Minerals & Metallic Materials Inspection Center of Tianjin Customs , Tianjin 300456 , People's Republic of China
| |
Collapse
|
24
|
Wang K, Qu C, Wang J, Ouyang W, Ma M, Zheng Q. Strain Engineering Modulates Graphene Interlayer Friction by Moiré Pattern Evolution. ACS APPLIED MATERIALS & INTERFACES 2019; 11:36169-36176. [PMID: 31486630 DOI: 10.1021/acsami.9b09259] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The sliding friction of a graphene flake atop strained graphene substrates is studied using molecular dynamics simulation. We demonstrate that in this superlubric system, friction can be reduced nonmonotonically by applying strain, which differs from previously reported results on various 2D materials. The critical strain needed for significant reduction in friction decreases drastically when the flake size increases. For a 250 nm flake, a 0.1% biaxial strain could lead to a more than 2-order-of-magnitude reduction. The underlying mechanism is revealed to be the evolution of Moiré patterns. The area of the Moiré pattern relative to the flake size plays a central role in determining friction in strain engineering and other scenarios of superlubricity as well. This result suggests that strain engineering could be particularly efficient for friction modification with large contacts.
Collapse
Affiliation(s)
| | | | | | - Wengen Ouyang
- Department of Physical Chemistry, School of Chemistry , Tel Aviv University , Tel Aviv 6997801 , Israel
| | | | | |
Collapse
|
25
|
Qu C, Shi S, Ma M, Zheng Q. Rotational Instability in Superlubric Joints. PHYSICAL REVIEW LETTERS 2019; 122:246101. [PMID: 31322388 DOI: 10.1103/physrevlett.122.246101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 03/15/2019] [Indexed: 06/10/2023]
Abstract
Surface and interfacial energies play important roles in a number of instability phenomena in liquids and soft matter, but rarely have similar effects in solids. Here, a mechanical instability is reported which is controlled by surface and interfacial energies and is valid for a large class of materials, in particular two-dimensional layered materials. When sliding a top flake cleaved from a square microscale graphite mesa by using a probe acting on the flake through a point contact, it was observed that the flake moved unrotationally for a certain distance before it suddenly transferred to a rotating-moving state. The theoretical analysis was consistent with the experimental observation and revealed that this mechanical instability was an interesting effect of the structural superlubricity (a state of nearly zero friction). Further analysis showed that this type of instability was applicable generally for various sliding joints on different scales, as long as the friction was ultralow. Thus, the uncovered mechanism provides useful knowledge for manipulating and controlling these sliding joints, and can guide the design of future superlubricity-based devices.
Collapse
Affiliation(s)
- Cangyu Qu
- Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China
| | - Songlin Shi
- Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China
| | - Ming Ma
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
- Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China
| | - Quanshui Zheng
- Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| |
Collapse
|
26
|
Mandelli D, Ouyang W, Hod O, Urbakh M. Negative Friction Coefficients in Superlubric Graphite-Hexagonal Boron Nitride Heterojunctions. PHYSICAL REVIEW LETTERS 2019; 122:076102. [PMID: 30848642 DOI: 10.1103/physrevlett.122.076102] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 12/03/2018] [Indexed: 06/09/2023]
Abstract
Negative friction coefficients, where friction is reduced upon increasing normal load, are predicted for superlubric graphite-hexagonal boron nitride heterojunctions. The origin of this counterintuitive behavior lies in the load-induced suppression of the moiré superstructure out-of-plane distortions leading to a less dissipative interfacial dynamics. Thermally induced enhancement of the out-of-plane fluctuations leads to an unusual increase of friction with temperature. The highlighted frictional mechanism is of a general nature and is expected to appear in many layered material heterojunctions.
Collapse
Affiliation(s)
- Davide Mandelli
- Department of Physical Chemistry, School of Chemistry, The Raymond and Beverly Sackler Faculty of Exact Sciences and The Sackler Center for Computational Molecular and Materials Science, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Wengen Ouyang
- Department of Physical Chemistry, School of Chemistry, The Raymond and Beverly Sackler Faculty of Exact Sciences and The Sackler Center for Computational Molecular and Materials Science, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Oded Hod
- Department of Physical Chemistry, School of Chemistry, The Raymond and Beverly Sackler Faculty of Exact Sciences and The Sackler Center for Computational Molecular and Materials Science, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Michael Urbakh
- Department of Physical Chemistry, School of Chemistry, The Raymond and Beverly Sackler Faculty of Exact Sciences and The Sackler Center for Computational Molecular and Materials Science, Tel Aviv University, Tel Aviv 6997801, Israel
| |
Collapse
|
27
|
Wang K, Ouyang W, Cao W, Ma M, Zheng Q. Robust superlubricity by strain engineering. NANOSCALE 2019; 11:2186-2193. [PMID: 30671572 DOI: 10.1039/c8nr07963c] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Structural superlubricity, a nearly frictionless state between two contact solid surfaces, has attracted rapidly increasing attention during the past few years. Yet a key problem that limits its promising applications is the high anisotropy of friction which always leads to its failure. Here we study the friction of a graphene flake sliding on top of a graphene substrate using molecular dynamics simulation. The results show that by applying strain on the substrate, biaxial stretching is better than uniaxial stretching in terms of reducing interlayer friction. Importantly, we find that robust superlubricity can be achieved via both biaxial and uniaxial stretching, namely for stretching above a critical strain which has been achieved experimentally, the friction is no longer dependent on the relative orientation mainly due to the complete lattice mismatch. The underlying mechanism is revealed to be the Moiré pattern formed. These findings provide a viable approach for the realization of robust superlubricity through strain engineering.
Collapse
Affiliation(s)
- Kunqi Wang
- State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China. and Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China.
| | - Wengen Ouyang
- Department of Physical Chemistry, School of Chemistry, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Wei Cao
- State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China. and Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China.
| | - Ming Ma
- State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China. and Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China.
| | - Quanshui Zheng
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China. and Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
| |
Collapse
|
28
|
Structural superlubricity and ultralow friction across the length scales. Nature 2018; 563:485-492. [PMID: 30464268 DOI: 10.1038/s41586-018-0704-z] [Citation(s) in RCA: 149] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Accepted: 09/21/2018] [Indexed: 11/08/2022]
Abstract
Structural superlubricity, a state of ultralow friction and wear between crystalline surfaces, is a fundamental phenomenon in modern tribology that defines a new approach to lubrication. Early measurements involved nanometre-scale contacts between layered materials, but recent experimental advances have extended its applicability to the micrometre scale. This is an important step towards practical utilization of structural superlubricity in future technological applications, such as durable nano- and micro-electromechanical devices, hard drives, mobile frictionless connectors, and mechanical bearings operating under extreme conditions. Here we provide an overview of the field, including its birth and main achievements, the current state of the art and the challenges to fulfilling its potential.
Collapse
|
29
|
Li J, Li J, Luo J. Superlubricity of Graphite Sliding against Graphene Nanoflake under Ultrahigh Contact Pressure. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2018; 5:1800810. [PMID: 30479926 PMCID: PMC6247022 DOI: 10.1002/advs.201800810] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 07/03/2018] [Indexed: 05/06/2023]
Abstract
Superlubricity of graphite sliding against graphene can be easily attained at the nanoscale when it forms the incommensurate contact under a low contact pressure. However, the achievement of superlubricity under an ultrahigh contact pressure (>1 GPa), which has more applications in the lubrication of micromachine and nanomachine, remains unclear. Here, this problem is addressed and the robust superlubricity of graphite is obtained under ultrahigh contact pressures of up to 2.52 GPa, by the formation of transferred graphene nanoflakes on a silicon tip. The friction coefficient becomes as low as 0.0003, a state that is attributed to the extremely low shear strength of the graphene/graphite interface in the incommensurate contact. When the pressure exceeds some threshold, the superlubricity state collapses suddenly with the friction coefficient increasing ≈10 times. The failure of superlubricity originates from the delamination of the topmost graphene layers on graphite under ultrahigh contact pressures, which requires the tip to provide additional exfoliation energies during the sliding process. The results demonstrate that the superlubricity of graphite sliding against graphene can exist stably under ultrahigh contact pressure, which would appear to accelerate its application in nanoscale lubrication.
Collapse
Affiliation(s)
- Jinjin Li
- State Key Laboratory of TribologyTsinghua UniversityBeijing100084China
| | - Jianfeng Li
- State Key Laboratory of TribologyTsinghua UniversityBeijing100084China
| | - Jianbin Luo
- State Key Laboratory of TribologyTsinghua UniversityBeijing100084China
| |
Collapse
|
30
|
Song Y, Mandelli D, Hod O, Urbakh M, Ma M, Zheng Q. Robust microscale superlubricity in graphite/hexagonal boron nitride layered heterojunctions. NATURE MATERIALS 2018; 17:894-899. [PMID: 30061730 DOI: 10.1038/s41563-018-0144-z] [Citation(s) in RCA: 133] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 07/02/2018] [Indexed: 06/08/2023]
Abstract
Structural superlubricity is a fascinating tribological phenomenon, in which the lateral interactions between two incommensurate contacting surfaces are effectively cancelled resulting in ultralow sliding friction. Here we report the experimental realization of robust superlubricity in microscale monocrystalline heterojunctions, which constitutes an important step towards the macroscopic scale-up of superlubricity. The results for interfaces between graphite and hexagonal boron nitride clearly demonstrate that structural superlubricity persists even when the aligned contact sustains external loads under ambient conditions. The observed frictional anisotropy in the heterojunctions is found to be orders of magnitude smaller than that measured for their homogeneous counterparts. Atomistic simulations reveal that the underlying frictional mechanisms in the two cases originate from completely different dynamical regimes. Our results are expected to be of a general nature and should be applicable to other van der Waals heterostructures.
Collapse
Affiliation(s)
- Yiming Song
- State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing, China
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing, China
| | - Davide Mandelli
- Department of Physical Chemistry, School of Chemistry, The Raymond and Beverly Sackler Faculty of Exact Sciences and The Sackler Center for Computational Molecular and Materials Science, Tel Aviv University, Tel Aviv, Israel
| | - Oded Hod
- Department of Physical Chemistry, School of Chemistry, The Raymond and Beverly Sackler Faculty of Exact Sciences and The Sackler Center for Computational Molecular and Materials Science, Tel Aviv University, Tel Aviv, Israel
| | - Michael Urbakh
- Department of Physical Chemistry, School of Chemistry, The Raymond and Beverly Sackler Faculty of Exact Sciences and The Sackler Center for Computational Molecular and Materials Science, Tel Aviv University, Tel Aviv, Israel
| | - Ming Ma
- State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing, China.
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing, China.
| | - Quanshui Zheng
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing, China.
- Department of Engineering Mechanics, Tsinghua University, Beijing, China.
| |
Collapse
|
31
|
Ouyang W, Mandelli D, Urbakh M, Hod O. Nanoserpents: Graphene Nanoribbon Motion on Two-Dimensional Hexagonal Materials. NANO LETTERS 2018; 18:6009-6016. [PMID: 30109806 DOI: 10.1021/acs.nanolett.8b02848] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We demonstrate snake-like motion of graphene nanoribbons atop graphene and hexagonal boron nitride ( h-BN) substrates using fully atomistic nonequilibrium molecular dynamics simulations. The sliding dynamics of the edge-pulled nanoribbons is found to be determined by the interplay between in-plane ribbon elasticity and interfacial lattice mismatch. This results in an unusual dependence of the friction-force on the ribbon's length, exhibiting an initial linear rise that levels-off above a junction-dependent threshold value dictated by the pre-slip stress distribution within the slider. As part of this letter, we present the LAMMPS implementation of the registry-dependent interlayer potentials for graphene, h-BN, and their heterojunctions that were used herein, which provides enhanced performance and accuracy.
Collapse
Affiliation(s)
- Wengen Ouyang
- School of Chemistry and The Sackler Center for Computational Molecular and Materials Science , Tel Aviv University , Tel Aviv 6997801 , Israel
| | - Davide Mandelli
- School of Chemistry and The Sackler Center for Computational Molecular and Materials Science , Tel Aviv University , Tel Aviv 6997801 , Israel
| | - Michael Urbakh
- School of Chemistry and The Sackler Center for Computational Molecular and Materials Science , Tel Aviv University , Tel Aviv 6997801 , Israel
| | - Oded Hod
- School of Chemistry and The Sackler Center for Computational Molecular and Materials Science , Tel Aviv University , Tel Aviv 6997801 , Israel
| |
Collapse
|
32
|
Deng H, Ma M, Song Y, He Q, Zheng Q. Structural superlubricity in graphite flakes assembled under ambient conditions. NANOSCALE 2018; 10:14314-14320. [PMID: 30019038 DOI: 10.1039/c7nr09628c] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
To date, structural superlubricity in microscale contacts is mostly observed in intrinsic graphite flakes that are cleaved by shearing from HOPG mesas in situ or friction pairs assembled in vacuum due to the high requirement of ultra clean interface for superlubricity, which severely limits their practical applications. Herein, we report observations on microscale structural superlubricity in graphite flake pairs assembled under ambient conditions, where contaminants are inevitably present at the interfaces. For such friction pairs, we find a novel running-in phenomenon, where the friction decreases with reciprocating motions, but no morphological or chemical changes can be observed. The underlying mechanism for the new running-in process is revealed to be the removal of third bodies confined between the surfaces. Our results improve the understanding of microscale superlubricity and may help extend the practical applications of superlubricity.
Collapse
Affiliation(s)
- He Deng
- School of Mechanical Engineering, Southwest Jiaotong University, Chengdu 610031, PR China
| | | | | | | | | |
Collapse
|
33
|
Vanossi A, Dietzel D, Schirmeisen A, Meyer E, Pawlak R, Glatzel T, Kisiel M, Kawai S, Manini N. Recent highlights in nanoscale and mesoscale friction. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2018; 9:1995-2014. [PMID: 30116691 PMCID: PMC6071713 DOI: 10.3762/bjnano.9.190] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 06/27/2018] [Indexed: 05/31/2023]
Abstract
Friction is the oldest branch of non-equilibrium condensed matter physics and, at the same time, the least established at the fundamental level. A full understanding and control of friction is increasingly recognized to involve all relevant size and time scales. We review here some recent advances on the research focusing of nano- and mesoscale tribology phenomena. These advances are currently pursued in a multifaceted approach starting from the fundamental atomic-scale friction and mechanical control of specific single-asperity combinations, e.g., nanoclusters on layered materials, then scaling up to the meso/microscale of extended, occasionally lubricated, interfaces and driven trapped optical systems, and eventually up to the macroscale. Currently, this "hot" research field is leading to new technological advances in the area of engineering and materials science.
Collapse
Affiliation(s)
- Andrea Vanossi
- CNR-IOM Democritos National Simulation Center, Via Bonomea 265, 34136 Trieste, Italy
- International School for Advanced Studies (SISSA), Via Bonomea 265, 34136 Trieste, Italy
| | - Dirk Dietzel
- Institute of Applied Physics, University of Giessen, 33492 Giessen, Germany
| | - Andre Schirmeisen
- Institute of Applied Physics, University of Giessen, 33492 Giessen, Germany
| | - Ernst Meyer
- Department of Physics, University of Basel, Klingelbergstr. 82, CH-4056 Basel, Switzerland
| | - Rémy Pawlak
- Department of Physics, University of Basel, Klingelbergstr. 82, CH-4056 Basel, Switzerland
| | - Thilo Glatzel
- Department of Physics, University of Basel, Klingelbergstr. 82, CH-4056 Basel, Switzerland
| | - Marcin Kisiel
- Department of Physics, University of Basel, Klingelbergstr. 82, CH-4056 Basel, Switzerland
| | - Shigeki Kawai
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1, Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - Nicola Manini
- Dipartimento di Fisica, Università degli Studi di Milano, via Celoria 16, 20133 Milano, Italy
| |
Collapse
|
34
|
Li J, Gao T, Luo J. Superlubricity of Graphite Induced by Multiple Transferred Graphene Nanoflakes. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2018; 5:1700616. [PMID: 29593965 PMCID: PMC5867060 DOI: 10.1002/advs.201700616] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 11/06/2017] [Indexed: 05/19/2023]
Abstract
2D or 3D layered materials, such as graphene, graphite, and molybdenum disulfide, usually exhibit superlubricity properties when sliding occurs between the incommensurate interface lattices. This study reports the superlubricity between graphite and silica under ambient conditions, induced by the formation of multiple transferred graphene nanoflakes on the asperities of silica surfaces after the initial frictional sliding. The friction coefficient can be reduced to as low as 0.0003 with excellent robustness and is independent of the surface roughness, sliding velocities, and rotation angles. The superlubricity mechanism can be attributed to the extremely weak interaction and easy sliding between the transferred graphene nanoflakes and graphite in their incommensurate contact. This finding has important implications for developing approaches to achieve superlubricity of layered materials at the nanoscale by tribointeractions.
Collapse
Affiliation(s)
- Jinjin Li
- State Key Laboratory of TribologyTsinghua UniversityBeijing100084China
| | - Tianyang Gao
- State Key Laboratory of TribologyTsinghua UniversityBeijing100084China
| | - Jianbin Luo
- State Key Laboratory of TribologyTsinghua UniversityBeijing100084China
| |
Collapse
|
35
|
Zeng X, Peng Y, Liu L, Lang H, Cao X. Dependence of the friction strengthening of graphene on velocity. NANOSCALE 2018; 10:1855-1864. [PMID: 29309078 DOI: 10.1039/c7nr07517k] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Graphene shows great potential applications as a solid lubricant in micro- and nanoelectromechanical systems (MEMS/NEMS). An atomic-scale friction strengthening effect in a few initial atomic friction periods usually occurred on few-layer graphene. Here, velocity dependent friction strengthening was observed in atomic-scale frictional behavior of graphene by atomic force microscopy (AFM). The degree of the friction strengthening decreases with the increase of velocity first and then reaches a plateau. This could be attributed to the interaction potential between the tip and graphene at high velocity which is weaker than that at low velocity, because the strong tip-graphene contact interface needs a longer time to evolve. The subatomic-scale stick-slip behavior in the conventional stick-slip motion supports the weak interaction between the tip and graphene at high velocity. These findings can provide a deeper understanding of the atomic-scale friction mechanism of graphene and other two-dimensional materials.
Collapse
Affiliation(s)
- Xingzhong Zeng
- College of Mechanical Engineering, Donghua University, Shanghai 201620, China.
| | | | | | | | | |
Collapse
|
36
|
Li JW, Wang TB, Liu NH, Yu T. Dependence of the sliding distance of a one-dimensional atom chain on initial velocity. Sci Rep 2017; 7:16290. [PMID: 29176611 PMCID: PMC5701177 DOI: 10.1038/s41598-017-16506-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 11/14/2017] [Indexed: 11/09/2022] Open
Abstract
In our daily lives, a body with a high initial velocity sliding freely on a rough surface moves a longer distance than that with a low initial velocity. However, such a phenomenon may not occur in the microscopic world. The dynamical behavior of a one-dimensional atom chain (1DAC) sliding on a substrate is investigated in this study by using a modified Frenkel–Kontorova model, in which the vibration of atoms on the substrate is considered. The dependence of sliding distance on initial velocity is examined. Result shows that although sliding distance is proportional to the initial value for most velocities, such a linear relation does not exist in some special velocities. This phenomenon is explained by a theoretical analysis of phonon excitation. The physical process is divided into three stages. The first stage is a superlubric sliding process with small amplitude of the vibrication of the atoms. The single-mode phonon is excited in the second stage. In the third stage, the system exhibits instability because of multiple-mode phonon excitations. In addition, the dependence of the coupling strength between 1DAC and the substrate is investigated. The findings are helpful in understanding the energy dissipation mechanism of friction.
Collapse
Affiliation(s)
- Jian-Wen Li
- School of Materials Science and Engineering, Nanchang University, Nanchang, 330031, China.,Department of Science, Nanchang Institute of technology, Nanchang, 330099, China
| | - Tong-Biao Wang
- Department of physics, Nanchang University, Nanchang, 330031, China.
| | - Nian-Hua Liu
- Institute for Advanced Study, Nanchang University, Nanchang, 330031, China.
| | - Tianbao Yu
- Department of physics, Nanchang University, Nanchang, 330031, China
| |
Collapse
|
37
|
Zhao G, Li X, Huang M, Zhen Z, Zhong Y, Chen Q, Zhao X, He Y, Hu R, Yang T, Zhang R, Li C, Kong J, Xu JB, Ruoff RS, Zhu H. The physics and chemistry of graphene-on-surfaces. Chem Soc Rev 2017; 46:4417-4449. [DOI: 10.1039/c7cs00256d] [Citation(s) in RCA: 260] [Impact Index Per Article: 37.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
This review describes the major “graphene-on-surface” structures and examines the roles of their properties in governing the overall performance for specific applications.
Collapse
Affiliation(s)
- Guoke Zhao
- State Key Lab of New Ceramics and Fine Processing
- School of Materials Science and Engineering, and Center for Nano and Micro Mechanics
- Tsinghua University
- Beijing 100084
- China
| | - Xinming Li
- Department of Electronic Engineering
- The Chinese University of Hong Kong
- China
| | - Meirong Huang
- State Key Lab of New Ceramics and Fine Processing
- School of Materials Science and Engineering, and Center for Nano and Micro Mechanics
- Tsinghua University
- Beijing 100084
- China
| | - Zhen Zhen
- State Key Lab of New Ceramics and Fine Processing
- School of Materials Science and Engineering, and Center for Nano and Micro Mechanics
- Tsinghua University
- Beijing 100084
- China
| | - Yujia Zhong
- State Key Lab of New Ceramics and Fine Processing
- School of Materials Science and Engineering, and Center for Nano and Micro Mechanics
- Tsinghua University
- Beijing 100084
- China
| | - Qiao Chen
- State Key Lab of New Ceramics and Fine Processing
- School of Materials Science and Engineering, and Center for Nano and Micro Mechanics
- Tsinghua University
- Beijing 100084
- China
| | - Xuanliang Zhao
- State Key Lab of New Ceramics and Fine Processing
- School of Materials Science and Engineering, and Center for Nano and Micro Mechanics
- Tsinghua University
- Beijing 100084
- China
| | - Yijia He
- State Key Lab of New Ceramics and Fine Processing
- School of Materials Science and Engineering, and Center for Nano and Micro Mechanics
- Tsinghua University
- Beijing 100084
- China
| | - Ruirui Hu
- State Key Lab of New Ceramics and Fine Processing
- School of Materials Science and Engineering, and Center for Nano and Micro Mechanics
- Tsinghua University
- Beijing 100084
- China
| | - Tingting Yang
- State Key Lab of New Ceramics and Fine Processing
- School of Materials Science and Engineering, and Center for Nano and Micro Mechanics
- Tsinghua University
- Beijing 100084
- China
| | - Rujing Zhang
- State Key Lab of New Ceramics and Fine Processing
- School of Materials Science and Engineering, and Center for Nano and Micro Mechanics
- Tsinghua University
- Beijing 100084
- China
| | - Changli Li
- State Key Lab of New Ceramics and Fine Processing
- School of Materials Science and Engineering, and Center for Nano and Micro Mechanics
- Tsinghua University
- Beijing 100084
- China
| | - Jing Kong
- Department of Electrical Engineering and Computer Sciences
- Massachusetts Institute of Technology
- Cambridge
- USA
| | - Jian-Bin Xu
- Department of Electronic Engineering
- The Chinese University of Hong Kong
- China
| | - Rodney S. Ruoff
- Center for Multidimensional Carbon Materials, Institute for Basic Science (IBS), and Department of Chemistry
- Ulsan National Institute of Science and Technology (UNIST)
- Ulsan
- Republic of Korea
| | - Hongwei Zhu
- State Key Lab of New Ceramics and Fine Processing
- School of Materials Science and Engineering, and Center for Nano and Micro Mechanics
- Tsinghua University
- Beijing 100084
- China
| |
Collapse
|
38
|
Calvo-Almazán I, Sacchi M, Tamtögl A, Bahn E, Koza MM, Miret-Artés S, Fouquet P. Ballistic Diffusion in Polyaromatic Hydrocarbons on Graphite. J Phys Chem Lett 2016; 7:5285-5290. [PMID: 27973887 DOI: 10.1021/acs.jpclett.6b02305] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
This work presents an experimental picture of molecular ballistic diffusion on a surface, a process that is difficult to pinpoint because it generally occurs on very short length scales. By combining neutron time-of-flight data with molecular dynamics simulations and density functional theory calculations, we provide a complete description of the ballistic translations and rotations of a polyaromatic hydrocarbon (PAH) adsorbed on the basal plane of graphite. Pyrene, C16H10, adsorbed on graphite is a unique system, where at relative surface coverages of about 10-20% its mean free path matches the experimentally accessible time/space scale of neutron time-of-flight spectroscopy (IN6 at the Institut Laue-Langevin). The comparison between the diffusive behavior of large and small PAHs such as pyrene and benzene adsorbed on graphite brings a strong experimental indication that the interaction between molecules is the dominating mechanism in the surface diffusion of polyaromatic hydrocarbons adsorbed on graphite.
Collapse
Affiliation(s)
- Irene Calvo-Almazán
- Cavendish Laboratory, University of Cambridge , J. J. Thomson Avenue, CB3 0HE Cambridge, United Kingdom
| | - Marco Sacchi
- Department of Chemistry, University of Surrey , GU2 7XH Guildford, United Kingdom
| | - Anton Tamtögl
- Cavendish Laboratory, University of Cambridge , J. J. Thomson Avenue, CB3 0HE Cambridge, United Kingdom
| | - Emanuel Bahn
- Institut Laue-Langevin , 71 Avenue des Martyrs, CS 20156, F-38042 Grenoble Cedex 9, France
| | - Marek M Koza
- Institut Laue-Langevin , 71 Avenue des Martyrs, CS 20156, F-38042 Grenoble Cedex 9, France
| | - Salvador Miret-Artés
- Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas , Serrano 123, E-28006 Madrid, Spain
| | - Peter Fouquet
- Institut Laue-Langevin , 71 Avenue des Martyrs, CS 20156, F-38042 Grenoble Cedex 9, France
| |
Collapse
|
39
|
Annett J, Cross GLW. Self-assembly of graphene ribbons by spontaneous self-tearing and peeling from a substrate. Nature 2016; 535:271-5. [PMID: 27411633 DOI: 10.1038/nature18304] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Accepted: 03/18/2016] [Indexed: 12/23/2022]
Abstract
Graphene and related two-dimensional materials have shown unusual and exceptional mechanical properties, with similarities to origami-like paper folding and kirigami-like cutting demonstrated. For paper analogues, a critical difference between macroscopic sheets and a two-dimensional solid is the molecular scale of the thin dimension of the latter, allowing the thermal activation of considerable out-of-plane motion. So far thermal activity has been shown to produce local wrinkles in a free graphene sheet that help in theoretically understanding its stability, for example, and give rise to unexpected long-range bending stiffness. Here we show that thermal activation can have a more marked effect on the behaviour of two-dimensional solids, leading to spontaneous and self-driven sliding, tearing and peeling from a substrate on scales approaching the macroscopic. We demonstrate that scalable nanoimprint-style contact techniques can nucleate and direct the parallel self-assembly of graphene ribbons of controlled shape in ambient conditions. We interpret our observations through a simple fracture-mechanics model that shows how thermodynamic forces drive the formation of the graphene-graphene interface in lieu of substrate contact with sufficient strength to peel and tear multilayer graphene sheets. Our results show how weak physical surface forces can be harnessed and focused by simple folded configurations of graphene to tear the strongest covalent bond. This effect may hold promise for the patterning and mechanical actuating of devices based on two-dimensional materials.
Collapse
Affiliation(s)
- James Annett
- Centre for Research on Adaptive Nanostructures and Nanodevices, Trinity College, Dublin 2, Ireland.,Advanced Materials and BioEngineering Research, Trinity College, Dublin 2, Ireland.,School of Physics, Trinity College, Dublin 2, Ireland
| | - Graham L W Cross
- Centre for Research on Adaptive Nanostructures and Nanodevices, Trinity College, Dublin 2, Ireland.,Advanced Materials and BioEngineering Research, Trinity College, Dublin 2, Ireland.,School of Physics, Trinity College, Dublin 2, Ireland
| |
Collapse
|
40
|
Motevalli B, Taherifar N, Liu JZ. Sustaining GHz oscillation of carbon nanotube based oscillators via a MHz frequency excitation. NANOTECHNOLOGY 2016; 27:205501. [PMID: 27070404 DOI: 10.1088/0957-4484/27/20/205501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
There have been intensive studies to investigate the properties of gigahertz nano-oscillators based on multi-walled carbon nanotubes (MWCNTs). Many of these studies, however, revealed that the unique telescopic translational oscillations in such devices would damp quickly due to various energy dissipation mechanisms. This challenge remains the primary obstacle against its practical applications. Herein, we propose a design concept in which a GHz oscillation could be re-excited by a MHz mechanical motion. This design involves a triple-walled CNT, in which sliding of the longer inner tube at a MHz frequency can re-excite and sustain a GHz oscillation of the shorter middle tube. Our molecular dynamics (MD) simulations prove this design concept at ∼10 nm scale. A mathematical model is developed to explore the feasibility at a larger size scale. As an example, in an oscillatory system with the CNT's length above 100 nm, the high oscillatory frequency range of 1.8-3.3 GHz could be excited by moving the inner tube at a much lower frequency of 53.4 MHz. This design concept together with the mechanical model could energize the development of GHz nano-oscillators in miniaturized electro-mechanical devices.
Collapse
Affiliation(s)
- Benyamin Motevalli
- Department of Mechanical and Aerospace Engineering, Monash University, Clayton, Victoria 3800, Australia
| | - Neda Taherifar
- Department of Mechanical and Aerospace Engineering, Monash University, Clayton, Victoria 3800, Australia
| | - Jefferson Zhe Liu
- Department of Mechanical and Aerospace Engineering, Monash University, Clayton, Victoria 3800, Australia
| |
Collapse
|
41
|
Woods CR, Withers F, Zhu MJ, Cao Y, Yu G, Kozikov A, Ben Shalom M, Morozov SV, van Wijk MM, Fasolino A, Katsnelson MI, Watanabe K, Taniguchi T, Geim AK, Mishchenko A, Novoselov KS. Macroscopic self-reorientation of interacting two-dimensional crystals. Nat Commun 2016; 7:10800. [PMID: 26960435 PMCID: PMC4792927 DOI: 10.1038/ncomms10800] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Accepted: 01/20/2016] [Indexed: 11/16/2022] Open
Abstract
Microelectromechanical systems, which can be moved or rotated with nanometre precision, already find applications in such fields as radio-frequency electronics, micro-attenuators, sensors and many others. Especially interesting are those which allow fine control over the motion on the atomic scale because of self-alignment mechanisms and forces acting on the atomic level. Such machines can produce well-controlled movements as a reaction to small changes of the external parameters. Here we demonstrate that, for the system of graphene on hexagonal boron nitride, the interplay between the van der Waals and elastic energies results in graphene mechanically self-rotating towards the hexagonal boron nitride crystallographic directions. Such rotation is macroscopic (for graphene flakes of tens of micrometres the tangential movement can be on hundreds of nanometres) and can be used for reproducible manufacturing of aligned van der Waals heterostructures.
Collapse
Affiliation(s)
- C. R. Woods
- School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - F. Withers
- School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - M. J. Zhu
- School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Y. Cao
- School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - G. Yu
- School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - A. Kozikov
- School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - M. Ben Shalom
- School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - S. V. Morozov
- School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK
- Institute of Microelectronics Technology and High Purity Materials RAS, Chernogolovka 142432, Russia
- National University of Science and Technology ‘MISiS', Moscow 119049, Russia
| | - M. M. van Wijk
- Institute for Molecules and Materials,Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - A. Fasolino
- Institute for Molecules and Materials,Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - M. I. Katsnelson
- Institute for Molecules and Materials,Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - K. Watanabe
- National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - T. Taniguchi
- National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - A. K. Geim
- Centre for Mesoscience and Nanotechnology, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - A. Mishchenko
- National Graphene Institute, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - K. S. Novoselov
- School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK
- National Graphene Institute, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| |
Collapse
|
42
|
Ouyang W, Ma M, Zheng Q, Urbakh M. Frictional Properties of Nanojunctions Including Atomically Thin Sheets. NANO LETTERS 2016; 16:1878-1883. [PMID: 26829154 DOI: 10.1021/acs.nanolett.5b05004] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Using nonequilibrium molecular dynamics simulations and a coarse-grained description of a system, we have investigated frictional properties of nanojunctions including atomically thin sheets embedded between metal surfaces. We found that the frictional properties of the junctions are determined by the interplay between the lattice mismatch of the contacting surfaces and out-of-plane displacements of the sheet. The simulations provide insight into how and why the frictional characteristics of the nanojunctions are affected by the commensurate-incommensurate transition. We demonstrated that in order to achieve a superlow friction, the graphene sheet should be grown on or transferred to the surface with morphology, which is close to that of the graphene (for instance, Cu), while the second confining surface should be incommensurate with the graphene (e.g., Au). Our results suggest an avenue for controlling nanoscale friction in layered materials and provide insights in the design of heterojunctions for nanomechanical applications.
Collapse
Affiliation(s)
| | - Ming Ma
- School of Chemistry, Tel Aviv University , Tel Aviv 69978, Israel
- The Sackler Center for Computational Molecular and Materials Science, Tel Aviv University , Tel Aviv 69978, Israel
| | | | - Michael Urbakh
- School of Chemistry, Tel Aviv University , Tel Aviv 69978, Israel
- The Sackler Center for Computational Molecular and Materials Science, Tel Aviv University , Tel Aviv 69978, Israel
| |
Collapse
|
43
|
|
44
|
Abstract
The basal plane cleavage energy (CE) of graphite is a key material parameter for understanding many of the unusual properties of graphite, graphene and carbon nanotubes. Nonetheless, a wide range of values for the CE has been reported and no consensus has yet emerged. Here we report the first direct, accurate experimental measurement of the CE of graphite using a novel method based on the self-retraction phenomenon in graphite. The measured value, 0.37±0.01 J m−2 for the incommensurate state of bicrystal graphite, is nearly invariant with respect to temperature (22 °C≤T≤198 °C) and bicrystal twist angle, and insensitive to impurities from the atmosphere. The CE for the ideal ABAB graphite stacking, 0.39±0.02 J m−2, is calculated based on a combination of the measured CE and a theoretical calculation. These experimental measurements are also ideal for use in evaluating the efficacy of competing theoretical approaches. Knowing the cleavage energy of graphite layers is important to understand the mechanical properties of graphite, graphene and related compounds. Here, the authors report a high accuracy experimental measurement of the cleavage energy and validation through multiscale modelling.
Collapse
|
45
|
Ye Z, Otero-de-la-Roza A, Johnson ER, Martini A. Oscillatory motion in layered materials: graphene, boron nitride, and molybdenum disulfide. NANOTECHNOLOGY 2015; 26:165701. [PMID: 25815685 DOI: 10.1088/0957-4484/26/16/165701] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Offset-driven self-retraction and oscillatory motion of bilayer graphene has been observed experimentally and is potentially relevant for nanoscale technological applications. In a previous article, we showed that friction between laterally offset graphene layers is controlled by roughness and proposed a simple reduced-order model based on density-functional theory (DFT) and molecular dynamics (MD) data, with which predictions on the experimental size-scale could be made. In this article, we extend our study to other layered materials, with emphasis on boron nitride (BN) and molybdenum disulfide (MoS2). Using MD and DFT simulations of these systems and a generalized version of the reduced-order model, we predict that BN will exhibit behavior similar to graphene (heavily-damped oscillation with a decay rate that increases with roughness) and that MoS2 shows no oscillatory behavior even in the absence of roughness. This is attributed to the higher energy barrier for sliding in MoS2 as well as the surface structure. Our generalized reduced-order model provides a guide to predicting and tuning experimental oscillation behavior using a few parameters that can be derived from simulation data.
Collapse
Affiliation(s)
- Zhijiang Ye
- School of Engineering, University of California Merced, 5200 N. Lake Road, Merced, CA, 95343, USA
| | | | | | | |
Collapse
|
46
|
Paci JT, Furmanchuk A, Espinosa HD, Schatz GC. Shear and friction between carbon nanotubes in bundles and yarns. NANO LETTERS 2014; 14:6138-6147. [PMID: 25279773 DOI: 10.1021/nl502210r] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We perform a detailed density functional theory assessment of the factors that determine shear interactions between carbon nanotubes (CNTs) within bundles and in related CNT and graphene structures including yarns, providing an explanation for the shear force measured in recent experiments (Filleter, T. etal. Nano Lett. 2012, 12, 73). The potential energy barriers separating AB stacked structures are found to be irrelevant to the shear analysis for bundles and yarns due to turbostratic stacking, and as a result, the tube-tube shear strength for pristine CNTs is estimated to be <0.24 MPa, that is, extremely small. Instead, it is pinning due to the presence of defects and functional groups at the tube ends that primarily cause resistance to shear when bundles are fractured in weak vacuum (∼10(-5) Torr). Such defects and groups are estimated to involve 0.55 eV interaction energies on average, which is much larger than single-atom vacancy defects (approximately 0.039 eV). Furthermore, because graphitic materials are stiff they have large coherence lengths, and this means that push-pull effects result in force cancellation for vacancy and other defects that are internal to the CNTs. Another important factor is the softness of cantilever structures relative to the stiff CNTs in the experiments, as this contributes to elastic instability transitions that account for significant dissipation during shear that has been observed. The application of these results to the mechanical behavior of yarns is discussed, providing general guidelines for the manufacture of strong yarns composed of CNTs.
Collapse
Affiliation(s)
- Jeffrey T Paci
- Department of Chemistry and ‡Department of Mechanical Engineering, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
| | | | | | | |
Collapse
|
47
|
Ye Z, Otero-de-la-Roza A, Johnson ER, Martini A. The role of roughness-induced damping in the oscillatory motion of bilayer graphene. NANOTECHNOLOGY 2014; 25:425703. [PMID: 25274535 DOI: 10.1088/0957-4484/25/42/425703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
A multi-scale theoretical model is presented that is the first to offer quantitative agreement with experimental measurements of self-retraction and oscillation of bilayer graphene. The model integrates density-functional theory calculations of the energetics driving flake retraction and molecular-dynamics simulations capturing the dynamic response of laterally-offset rough surfaces. We demonstrate that nanoscale roughness explains self-retraction motion and propose a recipe for tuning that motion by controlling friction.
Collapse
Affiliation(s)
- Zhijiang Ye
- School of Engineering, University of California, Merced, 5200 N. Lake Road, Merced, CA 95343, USA
| | | | | | | |
Collapse
|
48
|
Liu Y, Grey F, Zheng Q. The high-speed sliding friction of graphene and novel routes to persistent superlubricity. Sci Rep 2014; 4:4875. [PMID: 24786521 PMCID: PMC4007076 DOI: 10.1038/srep04875] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Accepted: 04/15/2014] [Indexed: 11/17/2022] Open
Abstract
Recent experiments on microscopic graphite mesas demonstrate reproducible high-speed microscale superlubricity, even under ambient conditions. Here, we explore the same phenomenon on the nanoscale, by studying a graphene flake sliding on a graphite substrate, using molecular dynamics. We show that superlubricity is punctuated by high-friction transients as the flake rotates through successive crystallographic alignments with the substrate. Further, we introduce two novel routes to suppress frictional scattering and achieve persistent superlubricity. We use graphitic nanoribbons to eliminate frictional scattering by constraining the flake rotation, an approach we call frictional waveguides. We can also effectively suppress frictional scattering by biaxial stretching of the graphitic substrate. These new routes to persistent superlubricity at the nanoscale may guide the design of ultra-low dissipation nanomechanical devices.
Collapse
Affiliation(s)
- Yilun Liu
- 1] International Center for Applied Mechanics, SV Lab, School of Aerospace, Xi'an Jiaotong University, Xi'an 710049, China [2] Centre for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China
| | - François Grey
- 1] Centre for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China [2] Department of Physics, Tsinghua University, Beijing 100084, China [3] London Centre for Nanotechnology, University College London, London WC1H OAH, U.K [4] Centre Universitaire d'Informatique, University of Geneva, CH-1227 Carouge, Switzerland
| | - Quanshui Zheng
- 1] Centre for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China [2] Department of Engineering Mechanics, Applied Mechanics Lab, and State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| |
Collapse
|
49
|
A shear localization mechanism for lubricity of amorphous carbon materials. Sci Rep 2014; 4:3662. [PMID: 24412998 PMCID: PMC3888979 DOI: 10.1038/srep03662] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Accepted: 12/17/2013] [Indexed: 11/08/2022] Open
Abstract
Amorphous carbon is one of the most lubricious materials known, but the mechanism is not well understood. It is counterintuitive that such a strong covalent solid could exhibit exceptional lubricity. A prevailing view is that lubricity of amorphous carbon results from chemical passivation of dangling bonds on surfaces. Here we show instead that lubricity arises from shear induced strain localization, which, instead of homogeneous deformation, dominates the shearing process. Shear localization is characterized by covalent bond reorientation, phase transformation and structural ordering preferentially in a localized region, namely tribolayer, resulting in shear weakening. We further demonstrate an anomalous pressure induced transition from stick-slip friction to continuous sliding with ultralow friction, due to gradual clustering and layering of graphitic sheets in the tribolayer. The proposed shear localization mechanism sheds light on the mechanism of superlubricity, and would enrich our understanding of lubrication mechanism of a wide variety of amorphous materials.
Collapse
|