An improved arc discharge method is developed to fabricate carbon nanotube probe of atomic force microscopy （AFM） here. First, silicon probe and carbon nanotube are manipulated under an optical microscope by two hig...An improved arc discharge method is developed to fabricate carbon nanotube probe of atomic force microscopy （AFM） here. First, silicon probe and carbon nanotube are manipulated under an optical microscope by two high precision microtranslators. When silicon probe and carbon nanotube are very close, several tens voltage is applied between them. And carbon nanotube is divided and attached to the end of silicon probe, which mainly due to the arc welding function. Comparing with the arc discharge method before, the new method here needs no coat silicon probe with metal film in advance, which can greatly reduce the fabrication＇s difficulty. The fabricated carbon nanotube probe shows good property of higher aspect ratio and can more accurately reflect the true topography of silicon grating than silicon probe. Under the same image drive force, carbon nanotube probe had less indentation depth on soft triblock copolymer sample than silicon probe. This showed that carbon nanotube probe has lower spring constant and less damage to the scan sample than silicon probe.展开更多
In this paper, three different tips are employed, i.e., the carbon nanotube tip, monocrystalline silicon tip and silicon nitride tip. Resorting to atomic force microscope （AFM）, they are used for measuring the surfa...In this paper, three different tips are employed, i.e., the carbon nanotube tip, monocrystalline silicon tip and silicon nitride tip. Resorting to atomic force microscope （AFM）, they are used for measuring the surface roughness of indium tin oxide （ITO） film and the immunoglobulin G （IgG） proteins within the scanning area of 10 μm×10 μm and 0.5 μm×0.5 μm, respectively. Subsequently, the scanned surface of the ITO film and IgG proteins are analyzed by using fractal dimension. The results show that the ffactal dimension measured by carbon nanotube tip is biggest with the highest frequency components and the most microscopic information. Therefore, the carbon nanotube tip is the ideal measuring tool for measuring super-smooth surface, which will play a more and more important role in the high-resolution imaging field.展开更多
Ordinary AFM probes'characters prevent the AFM' s application in various scopes. Carbon nanotubes represent ideal AFM probe materials for their higher aspect ratio, larger Young's modulus, unique chemical ...Ordinary AFM probes'characters prevent the AFM' s application in various scopes. Carbon nanotubes represent ideal AFM probe materials for their higher aspect ratio, larger Young's modulus, unique chemical structure, and well-defined electronic property. Carbon nanotube AFM probes are obtained by using a new method of attaching carbon nanotubes to the end of ordinary AFM probes, and are then used for doing AFM experiments. These experiments indicated that carbon nanotube probes have higher elastic deformation, higher resolution and higher durability. And it was also found that carbon nanotube probes ean accurately reflect the morphology of deep narrow gaps, while ordinary probes can not reflect.展开更多
An improved arc discharge method is developed to fabricate the carbon nanotube probe. In this method, the silicon probe and the carbon nanotube were manipulated under an optical microscope. When the silicon probe and ...An improved arc discharge method is developed to fabricate the carbon nanotube probe. In this method, the silicon probe and the carbon nanotube were manipulated under an optical microscope. When the silicon probe and the carbon nanotube were very close, 30-60 V dc or ae was applied between them, and the carbon nanotube was divided and attached to the end of the silicon probe. Comparing with the arc discharge method, the new method need not coat the silicon probe with metal in advance, which can greatly reduce the fabrication difficulty and cost. The fabricated carbon nanotube probe exhibits the good property of high aspect ratio and can reflect the true topography more accurately than the silicon probe.展开更多
The existence of excess sodium dodecyl sulfate(SDS)molecules in a single-walled carbon nanotube(SWNT)solution dispersed by hybridization with SDS leads to unstable atomic force microscopy(AFM)imaging.In this study,we ...The existence of excess sodium dodecyl sulfate(SDS)molecules in a single-walled carbon nanotube(SWNT)solution dispersed by hybridization with SDS leads to unstable atomic force microscopy(AFM)imaging.In this study,we demonstrate sequential dialysis against pure water in order to remove excess SDS molecules from an SDS-SWNT hybrid dispersion.A 1:102 volume ratio of SDS-SWNT dispersion to water in the dialysis was found to be effective in realizing stable AFM observations of the SDS-SWNT hybrids despite imperfect filtering of SDS via dialysis.On the other hand,the SDS-SWNT hybrids were stable even when this volume ratio was 1:106.Further,the SDS-SWNT hybrids were present in the solution even when the dialyzed samples were stored for 14 days.Our results reveal that dialysis under optimal conditions enables improved handling of SDS-SWNT hybrids,particularly for stable AFM observations.展开更多
One-dimensional carbon nanotube(CNT)exhibits excellent mechanical properties and is considered to be an ideal candidate material for the space elevator.However,subtle changes in its chirality strongly affect its physi...One-dimensional carbon nanotube(CNT)exhibits excellent mechanical properties and is considered to be an ideal candidate material for the space elevator.However,subtle changes in its chirality strongly affect its physical and chemical properties,including mechanical properties(such as Young's modulus,YM).Theoretical studies reveal that the YMs of perfect single-walled carbon nanotubes(SWCNTs)are in the order of TPa and related to their structures.Nevertheless,due to the lack of SWCNTs samples with well-defined structures and the difficulties in mechanical tests on individual SWCNTs,the theoretical correlations between YM and structure of SWCNTs have not been verified and are still in debate,which directly influences the practical utilization of the excellent mechanical properties of SWCNTs.In this work,we have developed an experimental method to measure the YM of an individual micrometer-scale suspended CNT by atomic force microscopy.A distinct regularity is found between the YM and chirality(i.e.,chiral angle and diameter)of SWCNT in the experiment for the first time.By comparing the YMs of SWCNTs with similar diameters and different chiral angles,it manifests that the SWCNT with a near zigzag configuration has a larger YM.This finding suggests that the effect of SWCNT’s structures on the YMs cannot be ignored.The developed method of measuring YMs of SWCNTs will be valuable for further experimental research on the inherent physical and chemical properties of SWCNTs.展开更多
基金This project is supported by National Natural Science Foundation of China (No.50205006).
文摘An improved arc discharge method is developed to fabricate carbon nanotube probe of atomic force microscopy （AFM） here. First, silicon probe and carbon nanotube are manipulated under an optical microscope by two high precision microtranslators. When silicon probe and carbon nanotube are very close, several tens voltage is applied between them. And carbon nanotube is divided and attached to the end of silicon probe, which mainly due to the arc welding function. Comparing with the arc discharge method before, the new method here needs no coat silicon probe with metal film in advance, which can greatly reduce the fabrication＇s difficulty. The fabricated carbon nanotube probe shows good property of higher aspect ratio and can more accurately reflect the true topography of silicon grating than silicon probe. Under the same image drive force, carbon nanotube probe had less indentation depth on soft triblock copolymer sample than silicon probe. This showed that carbon nanotube probe has lower spring constant and less damage to the scan sample than silicon probe.
基金National Natural Science Foundation of China(No.50605012).
文摘In this paper, three different tips are employed, i.e., the carbon nanotube tip, monocrystalline silicon tip and silicon nitride tip. Resorting to atomic force microscope （AFM）, they are used for measuring the surface roughness of indium tin oxide （ITO） film and the immunoglobulin G （IgG） proteins within the scanning area of 10 μm×10 μm and 0.5 μm×0.5 μm, respectively. Subsequently, the scanned surface of the ITO film and IgG proteins are analyzed by using fractal dimension. The results show that the ffactal dimension measured by carbon nanotube tip is biggest with the highest frequency components and the most microscopic information. Therefore, the carbon nanotube tip is the ideal measuring tool for measuring super-smooth surface, which will play a more and more important role in the high-resolution imaging field.
基金Sponsored by the National Natural Science Foundation of China (Grant No. 50202006)the Multidisciline Scientific Research Foundation of Harbin Institute of Technology (Grant No. HIT. MD. 2001.04)
文摘Ordinary AFM probes'characters prevent the AFM' s application in various scopes. Carbon nanotubes represent ideal AFM probe materials for their higher aspect ratio, larger Young's modulus, unique chemical structure, and well-defined electronic property. Carbon nanotube AFM probes are obtained by using a new method of attaching carbon nanotubes to the end of ordinary AFM probes, and are then used for doing AFM experiments. These experiments indicated that carbon nanotube probes have higher elastic deformation, higher resolution and higher durability. And it was also found that carbon nanotube probes ean accurately reflect the morphology of deep narrow gaps, while ordinary probes can not reflect.
基金Sponsored by the National Natural Science Foundation of China(Grant No.50205006)
文摘An improved arc discharge method is developed to fabricate the carbon nanotube probe. In this method, the silicon probe and the carbon nanotube were manipulated under an optical microscope. When the silicon probe and the carbon nanotube were very close, 30-60 V dc or ae was applied between them, and the carbon nanotube was divided and attached to the end of the silicon probe. Comparing with the arc discharge method, the new method need not coat the silicon probe with metal in advance, which can greatly reduce the fabrication difficulty and cost. The fabricated carbon nanotube probe exhibits the good property of high aspect ratio and can reflect the true topography more accurately than the silicon probe.
基金supported by a Grant-in-Aid for Scientific Research(23540479)of Japan Society for the Promotion of Science(JSPS)。
文摘The existence of excess sodium dodecyl sulfate(SDS)molecules in a single-walled carbon nanotube(SWNT)solution dispersed by hybridization with SDS leads to unstable atomic force microscopy(AFM)imaging.In this study,we demonstrate sequential dialysis against pure water in order to remove excess SDS molecules from an SDS-SWNT hybrid dispersion.A 1:102 volume ratio of SDS-SWNT dispersion to water in the dialysis was found to be effective in realizing stable AFM observations of the SDS-SWNT hybrids despite imperfect filtering of SDS via dialysis.On the other hand,the SDS-SWNT hybrids were stable even when this volume ratio was 1:106.Further,the SDS-SWNT hybrids were present in the solution even when the dialyzed samples were stored for 14 days.Our results reveal that dialysis under optimal conditions enables improved handling of SDS-SWNT hybrids,particularly for stable AFM observations.
基金supported by the National Key R&D Program of China(Nos.2018YFA0208402 and 2020YFA0714700)the National Natural Science Foundation of China(Nos.52172060,51820105002,11634014 and 51372269)+1 种基金X.J.W.thanks Youth Innovation Promotion Association of the Chinese Academy of Sciences(No.2020005)One Hundred Talent Project of Institute of Physics,CAS.H.P.L.and X.Z.thank support by the“One Hundred talents project”of CAS.
文摘One-dimensional carbon nanotube(CNT)exhibits excellent mechanical properties and is considered to be an ideal candidate material for the space elevator.However,subtle changes in its chirality strongly affect its physical and chemical properties,including mechanical properties(such as Young's modulus,YM).Theoretical studies reveal that the YMs of perfect single-walled carbon nanotubes(SWCNTs)are in the order of TPa and related to their structures.Nevertheless,due to the lack of SWCNTs samples with well-defined structures and the difficulties in mechanical tests on individual SWCNTs,the theoretical correlations between YM and structure of SWCNTs have not been verified and are still in debate,which directly influences the practical utilization of the excellent mechanical properties of SWCNTs.In this work,we have developed an experimental method to measure the YM of an individual micrometer-scale suspended CNT by atomic force microscopy.A distinct regularity is found between the YM and chirality(i.e.,chiral angle and diameter)of SWCNT in the experiment for the first time.By comparing the YMs of SWCNTs with similar diameters and different chiral angles,it manifests that the SWCNT with a near zigzag configuration has a larger YM.This finding suggests that the effect of SWCNT’s structures on the YMs cannot be ignored.The developed method of measuring YMs of SWCNTs will be valuable for further experimental research on the inherent physical and chemical properties of SWCNTs.
