The Experts below are selected from a list of 195 Experts worldwide ranked by ideXlab platform
Xingcheng Xiao - One of the best experts on this subject based on the ideXlab platform.
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Viscoelastic behavior and force nature of thermo-reversible epoxy dry adhesives.
Macromolecular Rapid Communications, 2009Co-Authors: Ruomiao Wang, Xingcheng XiaoAbstract:: The gecko Adhesion phenomenon has stimulated efforts to produce synthetic patterned dry adhesives. Besides introducing surface patterns on dry adhesives, it is also highly desirable to understand their Intrinsic material properties. This communication reports the viscoelastic behavior of non-patterned epoxy elastomers exhibiting Intrinsic Adhesion that is much higher than that of elastomers typically used for structure patterning. The diverse molecular origin of the Adhesion is revealed through the study of Adhesion against various substrates.
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Reversible dry micro-fibrillar adhesives with thermally controllable Adhesion
Soft Matter, 2009Co-Authors: Metin Sitti, Xingcheng XiaoAbstract:This work reports thin-film terminated micro-fibrillar adhesives made of adhesive polymers and shape memory polymers as reversible dry adhesives with thermally controllable Adhesion. Structurally different adhesives were fabricated by coating a continuous thin layer of an elastomeric adhesive polymer onto either a flat or a fibrillar shape memory polymer surface. Experimental results exhibited that pull-off forces of the adhesives can be up to four times different depending on thermal conditions. These differences originate from the temperature dependence of either the Intrinsic Adhesion properties of the adhesive polymer and/or the stiffness of the sub-surface shape memory polymer.
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Reversible dry micro-fibrillar adhesives with thermally controllable Adhesion
Soft Matter, 2009Co-Authors: Seok Kim, Tao Xie, Metin Sitti, Xingcheng XiaoAbstract:This work reports thin-film terminated micro-fibrillar adhesives made of adhesive polymers and shape memory polymers as reversible dry adhesives with thermally controllable Adhesion. Structurally different adhesives were fabricated by coating a continuous thin layer of an elastomeric adhesive polymer onto either a flat or a fibrillar shape memory polymer surface. Experimental results exhibited that pull-off forces of the adhesives can be up to four times different depending on thermal conditions. These differences originate from the temperature dependence of either the Intrinsic Adhesion properties of the adhesive polymer and/or the stiffness of the sub-surface shape memory polymer. © 2009 The Royal Society of Chemistry.
Eui-sung Yoon - One of the best experts on this subject based on the ideXlab platform.
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Friction of chemically and topographically modified Si(100) surfaces
Wear, 2007Co-Authors: R. Arvind Singh, Eui-sung YoonAbstract:Abstract Silicon (Si (1 0 0)) is a typically used material in micro/nano-scale devices, such as micro/nano-electromechanical systems (MEMS/NEMS). However, Si (1 0 0) does not have good tribological properties and hence its surface needs to be treated either chemically or topographically to enhance its tribological performance. In this paper, the micro/nano-frictional property of chemically and topographically modified Si (1 0 0) surfaces was studied. Chemically modified surfaces of Si (1 0 0) include coating of diamond-like carbon (DLC) films (two different thicknesses) and two self-assembled monolayers (SAMs). Topographically modified surfaces of Si (1 0 0) include nano-patterned poly(methyl methacrylate) (PMMA) on silicon wafer, fabricated by the process of a capillarity-directed soft lithographic technique. At the nano-scale, friction was measured using an atomic force microscope (AFM) and at the micro-scale it was measured using a ball-on-flat type micro-tribotester. Results showed that at both nano- and micro-scales, the modified Si (1 0 0) surfaces exhibited enhanced friction behavior when compared to bare Si (1 0 0) surfaces. The improved nano-friction behavior of the modified surfaces was attributed to their lower Intrinsic Adhesion and reduced real area of contact. In the case of nano-patterns, the physical (geometrical) reduction in contact area contributed in decreasing their friction. At micro-scale, wear was observed in the test samples (except in the case of SAMs), which influenced their friction behavior. Further, as a novel bio-mimetic approach for tribological application at micro-scale, the surface topography of natural leaves of Lotus and Colocasia were replicated by capillary force lithography using two different molding techniques. Interestingly, these bio-mimetically engineered surfaces exhibited superior micro-friction behavior. Indeed, this could be the first bio-mimetic approach of creating effective tribological materials by the direct replication of natural surfaces.
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Friction of chemically and topographically modified Si (1 0 0) surfaces
Wear, 2007Co-Authors: R. Arvind Singh, Eui-sung YoonAbstract:Silicon (Si (1 0 0)) is a typically used material in micro/nano-scale devices, such as micro/nano-electromechanical systems (MEMS/NEMS). However, Si (1 0 0) does not have good tribological properties and hence its surface needs to be treated either chemically or topographically to enhance its tribological performance. In this paper, the micro/nano-frictional property of chemically and topographically modified Si (1 0 0) surfaces was studied. Chemically modified surfaces of Si (1 0 0) include coating of diamond-like carbon (DLC) films (two different thicknesses) and two self-assembled monolayers (SAMs). Topographically modified surfaces of Si (1 0 0) include nano-patterned poly(methyl methacrylate) (PMMA) on silicon wafer, fabricated by the process of a capillarity-directed soft lithographic technique. At the nano-scale, friction was measured using an atomic force microscope (AFM) and at the micro-scale it was measured using a ball-on-flat type micro-tribotester. Results showed that at both nano- and micro-scales, the modified Si (1 0 0) surfaces exhibited enhanced friction behavior when compared to bare Si (1 0 0) surfaces. The improved nano-friction behavior of the modified surfaces was attributed to their lower Intrinsic Adhesion and reduced real area of contact. In the case of nano-patterns, the physical (geometrical) reduction in contact area contributed in decreasing their friction. At micro-scale, wear was observed in the test samples (except in the case of SAMs), which influenced their friction behavior. Further, as a novel bio-mimetic approach for tribological application at micro-scale, the surface topography of natural leaves of Lotus and Colocasia were replicated by capillary force lithography using two different molding techniques. Interestingly, these bio-mimetically engineered surfaces exhibited superior micro-friction behavior. Indeed, this could be the first bio-mimetic approach of creating effective tribological materials by the direct replication of natural surfaces. © 2007 Elsevier B.V. All rights reserved.
Seok Kim - One of the best experts on this subject based on the ideXlab platform.
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Reversible dry micro-fibrillar adhesives with thermally controllable Adhesion
Soft Matter, 2009Co-Authors: Seok Kim, Tao Xie, Metin Sitti, Xingcheng XiaoAbstract:This work reports thin-film terminated micro-fibrillar adhesives made of adhesive polymers and shape memory polymers as reversible dry adhesives with thermally controllable Adhesion. Structurally different adhesives were fabricated by coating a continuous thin layer of an elastomeric adhesive polymer onto either a flat or a fibrillar shape memory polymer surface. Experimental results exhibited that pull-off forces of the adhesives can be up to four times different depending on thermal conditions. These differences originate from the temperature dependence of either the Intrinsic Adhesion properties of the adhesive polymer and/or the stiffness of the sub-surface shape memory polymer. © 2009 The Royal Society of Chemistry.
R. Arvind Singh - One of the best experts on this subject based on the ideXlab platform.
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Friction of chemically and topographically modified Si(100) surfaces
Wear, 2007Co-Authors: R. Arvind Singh, Eui-sung YoonAbstract:Abstract Silicon (Si (1 0 0)) is a typically used material in micro/nano-scale devices, such as micro/nano-electromechanical systems (MEMS/NEMS). However, Si (1 0 0) does not have good tribological properties and hence its surface needs to be treated either chemically or topographically to enhance its tribological performance. In this paper, the micro/nano-frictional property of chemically and topographically modified Si (1 0 0) surfaces was studied. Chemically modified surfaces of Si (1 0 0) include coating of diamond-like carbon (DLC) films (two different thicknesses) and two self-assembled monolayers (SAMs). Topographically modified surfaces of Si (1 0 0) include nano-patterned poly(methyl methacrylate) (PMMA) on silicon wafer, fabricated by the process of a capillarity-directed soft lithographic technique. At the nano-scale, friction was measured using an atomic force microscope (AFM) and at the micro-scale it was measured using a ball-on-flat type micro-tribotester. Results showed that at both nano- and micro-scales, the modified Si (1 0 0) surfaces exhibited enhanced friction behavior when compared to bare Si (1 0 0) surfaces. The improved nano-friction behavior of the modified surfaces was attributed to their lower Intrinsic Adhesion and reduced real area of contact. In the case of nano-patterns, the physical (geometrical) reduction in contact area contributed in decreasing their friction. At micro-scale, wear was observed in the test samples (except in the case of SAMs), which influenced their friction behavior. Further, as a novel bio-mimetic approach for tribological application at micro-scale, the surface topography of natural leaves of Lotus and Colocasia were replicated by capillary force lithography using two different molding techniques. Interestingly, these bio-mimetically engineered surfaces exhibited superior micro-friction behavior. Indeed, this could be the first bio-mimetic approach of creating effective tribological materials by the direct replication of natural surfaces.
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Friction of chemically and topographically modified Si (1 0 0) surfaces
Wear, 2007Co-Authors: R. Arvind Singh, Eui-sung YoonAbstract:Silicon (Si (1 0 0)) is a typically used material in micro/nano-scale devices, such as micro/nano-electromechanical systems (MEMS/NEMS). However, Si (1 0 0) does not have good tribological properties and hence its surface needs to be treated either chemically or topographically to enhance its tribological performance. In this paper, the micro/nano-frictional property of chemically and topographically modified Si (1 0 0) surfaces was studied. Chemically modified surfaces of Si (1 0 0) include coating of diamond-like carbon (DLC) films (two different thicknesses) and two self-assembled monolayers (SAMs). Topographically modified surfaces of Si (1 0 0) include nano-patterned poly(methyl methacrylate) (PMMA) on silicon wafer, fabricated by the process of a capillarity-directed soft lithographic technique. At the nano-scale, friction was measured using an atomic force microscope (AFM) and at the micro-scale it was measured using a ball-on-flat type micro-tribotester. Results showed that at both nano- and micro-scales, the modified Si (1 0 0) surfaces exhibited enhanced friction behavior when compared to bare Si (1 0 0) surfaces. The improved nano-friction behavior of the modified surfaces was attributed to their lower Intrinsic Adhesion and reduced real area of contact. In the case of nano-patterns, the physical (geometrical) reduction in contact area contributed in decreasing their friction. At micro-scale, wear was observed in the test samples (except in the case of SAMs), which influenced their friction behavior. Further, as a novel bio-mimetic approach for tribological application at micro-scale, the surface topography of natural leaves of Lotus and Colocasia were replicated by capillary force lithography using two different molding techniques. Interestingly, these bio-mimetically engineered surfaces exhibited superior micro-friction behavior. Indeed, this could be the first bio-mimetic approach of creating effective tribological materials by the direct replication of natural surfaces. © 2007 Elsevier B.V. All rights reserved.
Metin Sitti - One of the best experts on this subject based on the ideXlab platform.
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Reversible dry micro-fibrillar adhesives with thermally controllable Adhesion
Soft Matter, 2009Co-Authors: Metin Sitti, Xingcheng XiaoAbstract:This work reports thin-film terminated micro-fibrillar adhesives made of adhesive polymers and shape memory polymers as reversible dry adhesives with thermally controllable Adhesion. Structurally different adhesives were fabricated by coating a continuous thin layer of an elastomeric adhesive polymer onto either a flat or a fibrillar shape memory polymer surface. Experimental results exhibited that pull-off forces of the adhesives can be up to four times different depending on thermal conditions. These differences originate from the temperature dependence of either the Intrinsic Adhesion properties of the adhesive polymer and/or the stiffness of the sub-surface shape memory polymer.
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Reversible dry micro-fibrillar adhesives with thermally controllable Adhesion
Soft Matter, 2009Co-Authors: Seok Kim, Tao Xie, Metin Sitti, Xingcheng XiaoAbstract:This work reports thin-film terminated micro-fibrillar adhesives made of adhesive polymers and shape memory polymers as reversible dry adhesives with thermally controllable Adhesion. Structurally different adhesives were fabricated by coating a continuous thin layer of an elastomeric adhesive polymer onto either a flat or a fibrillar shape memory polymer surface. Experimental results exhibited that pull-off forces of the adhesives can be up to four times different depending on thermal conditions. These differences originate from the temperature dependence of either the Intrinsic Adhesion properties of the adhesive polymer and/or the stiffness of the sub-surface shape memory polymer. © 2009 The Royal Society of Chemistry.
