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Bioinspired Dry Adhesive Materials and Their Application in Robotics： A Review

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Journal of Bionic Engineering 2016年第2期13卷 181-199页

作者： Yasong Li Jeffrey Krahn Carlo Menon MENRVA Research Group School of Engineering Science Simon Fraser University 8888 University Drive Burnaby BC V5A 1S6 Canada

Dry adhesives inspired from climbing animals, such as geckos and spiders, rely on van der waals forces to attach to the opposing surface. Biological fibrillar dry adhesives have a hierarchical structure closely resembling a tree： the surface of the skin on the animal＇s feet is covered in arrays of slender micro-fibrils, each of which supports arrays of fibrils in submicron dimensions. These nano-meter size fibrils can conform closely to the opposing surfaces to induce van der waals interaction. Bioinspired dry adhesives have been developed in research laboratories for more than a decade. To mimic the biological fibrillar adhesives, fibrillar structures have been prepared using a variety of materials and geometrical arrangements. In this review article, the mechanism and selected fabrication methods of fibrillar adhesives are summarized for future reference in adhesive development. Robotic applications of these bioinspired adhesives are also introduced in this article. Various successful appli- cations of bioinspired fibrillar adhesives can shed light on developing smart adhesives for use in automation.

关键词： bioinspired gecko adhesive van der waals forces biomimetic climbing robot bioinspired tape

Non-Contact to Contact Transition： Direct Measurements of Interaction forces between a Solid Probe and a Planar Air-Water Interface

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Chinese Physics Letters 2007年第10期24卷 2914-2917页

作者：吴迪王艺臻张进修 State Key Laboratory of Optoelectronic Materials and Technologies and Department of Physics Sun Yat-sen University Guangzhou 510275

The interaction force between a solid probe and a planar air-water interface is measured by using an atomic force microscope. It is demonstrated that during the approach of the probe to the air-water interface, the force curves decline all the time due to the van der waals attraction and induces a stable profile of water surface raised. When the tip approaches very close to the water surface, force curves jump suddenly, reflecting the complex behaviour of the unstable water surface. With a theoretical analysis we conclude that before the tip touches water surface, two water profiles appear, one stable and the other unstable. Then, with further approaching, the tip touches water surface and the non-contact to contact transition occurs.

关键词： PROBES (Electronic instruments) AIR WATER van der waals forces

Dynamic shell buckling behavior of multi-walled carbon nanotubes embedded in an elastic medium

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Science China(Physics,Mechanics & Astronomy) 2013年第3期56卷 483-490页

作者： SUN ChengQi LIU KaiXin HONG YouShi State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of Sciences LTCS and Department of Mechanics & Aerospace Engineering College of EngineeringPeking University

This paper studies the dynamic shell buckling behavior of multi-walled carbon nanotubes(MWNTs) embedded in an elastic medium under step axial load based on continuum mechanics *** is shown that,for occurrence of dynamic shell buckling of MWNTs or MWNTs embedded in an elastic medium,the buckling stress is higher than the critical buckling stress of the corresponding static shell buckling under otherwise identical *** results are demonstrated for dynamic shell buckling of individual double-walled carbon nanotubes(DWNTs) or DWNTs embedded in an elastic medium.A phenomenon is shown that DWNTs or embedded DWNTs in dynamic shell buckling are prone to axisymmetric buckling rather than non-axisymmetric *** results also indicate that the axial buckling form shifts from the lower buckling mode to the higher buckling mode with increasing buckling stress,but the buckling mode is invariable for a certain domain of buckling ***,an approximate analytic formula is presented for the buckling stress and the associated buckling wavelength for dynamic axisymmetric buckling of embedded *** effect of radii is also examined.

关键词： dynamic buckling carbon nanotube van der waals forces buckling stress buckling mode

Theoretical model of double-walled carbon nanotube pullout from a composite matrix

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Science China(Physics,Mechanics & Astronomy) 2012年第6期55卷 1004-1009页

作者： ZHOU LiJun KANG YiLan GUO JianGang Tianjin Key Laboratory of Modern Engineering Mechanics School of Mechanical EngineeringTianjin UniversityTianjin 300072China Department of Mechanical Engineering Tianjin University of Technology and EducationTianjin 300222China

A micromechanical model of double-walled carbon nanotube (DWCNT) pullout from a composite matrix is presented with the interfacial residual stress and van der waals (vdW) forces taken into *** interfacial residual stress induced by thermal expansion coefficient (TEC) mismatch is introduced via thermo-elastic constitutive *** influence of vdW interactions between two layers of DWCNT on the interfacial stress distributions of DWCNT and matrix is *** analytical expressions of interfacial shear stress and the axial stresses of DWCNT and matrix are derived,***,the influences of temperature change,interfacial friction coefficient,DWCNT aspect ratio,DWCNT volume fraction and the relative modulus between DWCNT and matrix are illustrated and discussed.

关键词： double-walled carbon nanotubes pullout residual stress van der waals forces

DYNAMIC BUCKLING BEHAVIOR OF MULTI-WALLED CARBON NANOTUBES SUBJECTED TO STEP AXIAL LOADING

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Acta Mechanica Solida Sinica 2012年第2期25卷 117-125页

作者： Chengqi Sun Kaixin Liu Youshi Hong State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of SciencesBeijing 100190China LTCS and Department of Mechanics&Aerospace Engineering College of EngineeringPeking UniversityBeijing 100871China

This paper studies the dynamic buckling behavior of multi-walled carbon nanotubes （MWNTs） subjected to step axial loading. A buckling condition is derived, and numerical results are presented for MWNTs under fixed boundary conditions. It is shown that the critical buckling load of MWNTs is of multi-branches and decreases as the time elongates. The associated buckling modes for different layers of MWNTs can be either in-phase or out of phase, which is related to the branch that the critical buckling load belongs to. For MWNTs with the same innermost tube radius, the critical buckling load is decreased when increasing the layers.

关键词： multi-walled carbon nanotubes dynamic buckling van der waals forces continuummechanics model

Manufacturable Novel Nanogrease with Superb Physical Properties

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Nanomanufacturing and Metrology 2021年第4期4卷 289-297页

作者： Hammad Younes Ding Lou Haiping Hong Huahui Chen Hongtao Liu Yinhuai Qiang Department of Electrical Engineering South Dakota School of Mines and TechnologyRapid CitySD 57701USA Department of Material Science and Engineering School of Mechanical and Electrical EngineeringChina University of Mining and TechnologyBeijing 100083China School of Material Science and Engineering China University of Mining and TechnologyXuzhou 221166China

High-performance nanogrease manufactured from carbon nanomaterials is observed to be stable and homogeneous and have superb physical properties,such as thermal and electrical conductivities,compared with current commercial greases made of lithium,calcium,and *** the first time,carbon nanomaterials have been observed to disperse well as the sole thickeners in oil systems,e.g.,polyalphaolefin and polyester(ROYCO),without the aid of any chemical ***-dimensional percolation network structures that exist among carbon nanomaterials are easily scalable,which can be attributed to the intermolecular van der waals ***,the introduction of hydrogen bonding in any form to grease significantly increases its thermal and electrical conductivities and substantially reduces the weight percentage of carbon nanomaterials needed to fabricate stable *** example,loading of only 1.4 wt%hydroxyl-functionalized multiwalled carbon nanotube(MWNT-OH)with Krytox XHT750 oil leads to a 37.8%increase in thermal ***,75%glycerol,25% water,and 4.5 wt% MWNT-OH yielded the lowest electrical resistivity of 10.0 Ω *** finding can be extended to hydrogen bonding materials with functional groups,such as OH,COOH,F,and *** nanogrease reported in this study has been manufactured using the three-roll mill method,which is an easy and cost-effective method,as the loading weight percentage of carbon nanomaterials to fabricate stable grease decreases from 12 wt% to 3-4 wt%.Furthermore,the process is easily scalable,reproduced,and *** novel high-performance nanogrease has a high commercial value and numerous applications and could replace current commercial greases.

关键词： Nanogrease Three-dimensional network percolation structure Carbon nanomaterial van der waals forces Hydrogen bonding Thermal conductivity Electrical conductivity

Investigating Interaction Between Biochanin A and Human Serum Albumin by Multi-spectroscopic and Molecular Simulation Methods

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Transactions of Tianjin University 2017年第4期23卷 325-333页

作者： Zhaohui Xue Aiqing Cheng Yanni Li Wancong Yu Xiaohong Kou School of Chemical Engineering and Technology Tianjin University Medical Plant Lab Tianjin Research Center of Agricultural Biotechnology

Biochanin A (BCA), the most abundant isoflavone in chickpeas, presents a wide range of biological activities, such as hypolipidaemic, anti-oxidative, anti-proliferative, and estrogen-like effects. We investigated the interaction between BCA and human serum albumin (HSA) via several techniques. UV–Vis absorption spectroscopy verified the conformational variation of HSA after BCA addition, and fluorescence spectroscopy revealed the relevant binding parameters. Circular dichroism spectroscopy was used to estimate the secondary structural changes of HSA with and without BCA. Molecular docking and dynamics simulations were then applied to study the characteristics of HSA with BCA. Energy decomposition analysis was used to prove that Trp214 in subdomain IIA of HSA is the most likely binding site of BCA. van der waals forces and hydrophobic interactions may play important roles during the binding process. All of our results showed that BCA presents significant binding affinity to HSA, thus confirming that the role of HSA has as an efficient transporter of biomolecules. © 2017, Tianjin University and Springer-Verlag Berlin Heidelberg.

关键词： Absorption spectroscopy Binding energy Bins Body fluids Dichroism Flavonoids Fluorescence spectroscopy Hydrophobicity Molecular biology Molecular dynamics van der waals forces

FLOW PROPERTIES OF COHESIVE NANOPOWderS

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China Particuology 2003年第6期1卷 231-241页

作者： Jgen Tomas Mechanical Process Engineering Process Engineering DepartmentThe Otto-von-Guericke-University MagdeburgUniversitsplatz2D39106 MagdeburgGermany

The fundamentals of cohesive powder consolidation and flow behaviour using a reasonable combination of particle and continuum mechanics are explained. By means of the model 搒tiff particles with soft contacts? the influ-ence of elastic-plastic repulsion in particle contacts is demonstrated. With this as the physical basis, the stationary yield locus, instantaneous yield loci and consolidation loci, flow function and compression function are presented. The flow properties of a very cohesive titania nanopowder (dS=200 nm) are shown. These models are used to evaluate shear cell test results as constitutive functions for computer aided apparatus design for reliable powder flow.

关键词： particle mechanics adhesion force van der waals forces constitutive models cohesive powder flow properties

Epitaxy of Ⅲ-nitrides on two-dimensional materials and its applications

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Chinese Physics B 2022年第11期31卷 23-35页

作者： Yu Xu Jianfeng Wang Bing Cao Ke Xu Suzhou Institute of Nano-Tech and Nano-Bionis(SINANO) Chinese Academy of Sciences(CAS)Suzhou 215123China Shenyang National Laboratory for Materials Science Shenyang 110010China School of Optoelectronic Science and Engineering&Collaborative Innovation Center of Suzhou Nano Science and Technology Soochow UniversitySuzhou 215006China Key Laboratory of Advanced Optical Manufacturing Technologies of Jiangsu Province&Key Laboratory of Modern Optical Technologies of Education Ministry of China Soochow UniversitySuzhou 215006China Jiangsu Institute of Advanced Semiconductors Ltd Suzhou 215123China

Ⅲ-nitride semiconductor materials have excellent optoelectronic properties,mechanical properties,and chemical stability,which have important applications in the field of optoelectronics and ***-dimensional(2D)materials have been widely focused in recent years due to their peculiar *** the property of weak bonding between layers of 2D materials,the growth ofⅢ-nitrides on 2D materials has been proposed to solve the mismatch problem caused by heterogeneous epitaxy and to develop substrate stripping techniques to obtain high-quality,low-cost nitride materials for high-quality nitride devices and their extension in the field of flexible *** this progress report,the main methods for the preparation of 2D materials,and the recent progress and applications of different techniques for the growth ofⅢ-nitrides based on 2D materials are reviewed.

关键词： nitrides two-dimensional materials van der waals forces