Because of their unique mechanical and electrical properties,zinc oxide(ZnO)nanowires are used widely in microscopic and nanoscopic devices and structures,but characterizing them remains challenging.In this paper,two ...Because of their unique mechanical and electrical properties,zinc oxide(ZnO)nanowires are used widely in microscopic and nanoscopic devices and structures,but characterizing them remains challenging.In this paper,two pick-up strategies are proposed for characterizing the electrical properties of ZnO nanowires using SEM equipped with a nanomanipulator.To pick up nanowires efficiently,direct sampling is compared with electrification fusing,and experiments show that direct sampling is more stable while electrification fusing is more efficient.ZnO nanowires have cut-off properties,and good Schottky contact with the tungsten probes was established.In piezoelectric experiments,the maximum piezoelectric voltage generated by an individual ZnO nanowire was 0.07 V,and its impedance decreased with increasing input signal frequency until it became stable.This work offers a technical reference for the pick-up and construction of nanomaterials and nanogeneration technology.展开更多
Single zinc oxide nanowires(ZnO NWs)are promising for nanogenerators because of their excellent semiconducting and piezoelectric properties,but characterizing the latter efficiently is challenging.As reported here,an ...Single zinc oxide nanowires(ZnO NWs)are promising for nanogenerators because of their excellent semiconducting and piezoelectric properties,but characterizing the latter efficiently is challenging.As reported here,an electrical breakdown strategy was used to construct single ZnO NWs with a specific length.With the high operability of a nanomanipulator in a scanning electron microscope,ZnO-NW-based twoprobe and three-probe structures were constructed for fabricating AC/DC nanogenerators,respectively.For a ZnO NW,an AC output of between−15.31 mV and 5.82 mV was achieved,while for a DC nanogenerator,an output of24.3 mV was realized.Also,the three-probe structure’s output method was changed to verify the distribution of piezoelectric charges when a single ZnO NW is bent by a probe,and DC outputs of different amplitudes were achieved.This study provides a low-cost,highly convenient,and operational method for studying the AC/DC output characteristics of single NWs,which is beneficial for the further development of nanogenerators.展开更多
Nanowires have emerged as promising one-dimensional materials with which to construct various nanocircuits and nanosensors.However,measuring the electrical properties of individual nanowires directly remains challengi...Nanowires have emerged as promising one-dimensional materials with which to construct various nanocircuits and nanosensors.However,measuring the electrical properties of individual nanowires directly remains challenging because of their small size,thereby hindering the comprehensive understanding of nanowire-based device performance.A crucial factor in achieving reliable electrical characterization is establishing well-determined contact conditions between the nanowire sample and the electrodes,which becomes particularly difficult for soft nanowires.Introduced here is a novel technique for measuring the conductivity of an individual nanowire with the aid of automated nanomanipulation using an atomic force microscope.In this method,two nanowire segments cut from the same silver nanowire are positioned onto a pair of gold electrodes,serving as flexible nanoprobes to establish controllable contact with the sample.By changing the contact points along the nanowire sample,conductivity measurements can be performed on different regions,thereby eliminating the influence of contact resistance by analyzing multiple current–voltage curves.Using this approach,the resistivity of a 100-nm-diameter silver nanowire is determined to be 3.49×10^(−8)Ωm.展开更多
In this study, atomic force microscope (AFM) tips are used as tools to cut and manipulate carbon nanotubes on various surfaces. The lateral forces acting on AFM tips during manipulation are also recorded and analyzed ...In this study, atomic force microscope (AFM) tips are used as tools to cut and manipulate carbon nanotubes on various surfaces. The lateral forces acting on AFM tips during manipulation are also recorded and analyzed from the perspective of micro-mechanics. It is found that differences in surface conditions can lead to obvious increase in micro-friction between nanotube and substrate. And also due to rehybridization, carbon nanotubes present excellent resilience when undergoing different degrees of strain. Finally, carbon nanotubes can complexly deform from elastic stage to plastic stage before complete rupture.展开更多
A scanning electron microscope(SEM)provides real-time imaging with nanometer resolution and a large scanning area,which enables the development and integration of robotic nanomanipulation systems inside a vacuum chamb...A scanning electron microscope(SEM)provides real-time imaging with nanometer resolution and a large scanning area,which enables the development and integration of robotic nanomanipulation systems inside a vacuum chamber to realize simultaneous imaging and direct interactions with nanoscaled samples.Emerging techniques for nanorobotic manipulation during SEM imaging enable the characterization of nanomaterials and nanostructures and the prototyping/assembly of nanodevices.This paper presents a comprehensive survey of recent advances in nanorobotic manipulation,including the development of nanomanipulation platforms,tools,changeable toolboxes,sensing units,control strategies,electron beam-induced deposition approaches,automation techniques,and nanomanipulation-enabled applications and discoveries.The limitations of the existing technologies and prospects for new technologies are also discussed.展开更多
The orientation and shifting of individual carbon nanotubes are extremely important in the assembly of building blocks of nanodevices and in the development of one-dimensional materials for interdisciplinary applicati...The orientation and shifting of individual carbon nanotubes are extremely important in the assembly of building blocks of nanodevices and in the development of one-dimensional materials for interdisciplinary applications.Here,we report an optical method that is capable of producing the controlled orientation and targeted shifting of single multiwalled carbon nanotubes(MWCNTs)using an optical-fiber nanotip.In a demonstration of this technique,a single MWCNT with an outer diameter of 50 nm and a length of 0.9 mm was first trapped by the nanotip using a laser beam with a wavelength of 980 nm and was then oriented and shifted along the nanotip axis as a result of the interaction of the MWCNT with the optical field output by the nanotip.Various optical powers were applied to characterize the orientation and shifting performance.The orientation and shifting of MWCNTs of various sizes were also demonstrated.展开更多
Nanomanipulation plays an important role in nanofabrication, it is also a technology necessary in exploring the secrets of nanoworld, and it thus becomes a start point to research future nanomachine. In this study, ma...Nanomanipulation plays an important role in nanofabrication, it is also a technology necessary in exploring the secrets of nanoworld, and it thus becomes a start point to research future nanomachine. In this study, manipulation and cutting of carbon nanotubes have been conducted in order to examine whether we can move a nano-component from one site to another by using the tip of atomic force microscope (AFM). The technique may also be valuable for providing the constructive materials of nanofabrication. While exploring the method for manipulating and cutting of nanotubes, some new phenomena have been observed during the process. Results show that carbon nanotubes present a feature of deformation combining bending and distortion when subjected to large mechanical forces exerted by the tip of AFM. In special cases, long carbon nanotubes can be cut into two parts, by which we can remove the part where crystal lattice is flawed, and therefore a perfect nanocomponent can be obtained.展开更多
Nanomanipulation under scanning electron microscopy(SEM)enables direct interactions of a tool with a sample.We recently developed a nanomanipulation technique for the extraction and identification of DNA contained wit...Nanomanipulation under scanning electron microscopy(SEM)enables direct interactions of a tool with a sample.We recently developed a nanomanipulation technique for the extraction and identification of DNA contained within sub-nuclear locations of a single cell nucleus.In nanomanipulation of sub-cellular structures,a key step is to identify targets of interest through correlating fluorescence and SEM images.The DNA extraction task must be conducted with low accelerating voltages resulting in low imaging resolutions.This is imposed by the necessity of preserving the biochemical integrity of the sample.Such poor imaging conditions make the identification of nanometer-sized fiducial marks difficult.This paper presents an affine scale-invariant feature transform(ASIFT)based method for correlating SEM images and fluorescence microscopy images.The performance of the image correlation approach under different noise levels and imaging magnifications was quantitatively evaluated.The optimal mean absolute error(MAE)of correlation results is 68634 nm under standard conditions.Compared with manual correlation by skilled operators,the automated correlation approach demonstrates a speed that is higher by an order of magnitude.With the SEM-fluorescence image correlation approach,targeted DNA was successfully extracted via nanomanipulation under SEM conditions.展开更多
基金supported by the Research Fund Program of the Guangdong Provincial Key Laboratory of Fuel Cell Technology。
文摘Because of their unique mechanical and electrical properties,zinc oxide(ZnO)nanowires are used widely in microscopic and nanoscopic devices and structures,but characterizing them remains challenging.In this paper,two pick-up strategies are proposed for characterizing the electrical properties of ZnO nanowires using SEM equipped with a nanomanipulator.To pick up nanowires efficiently,direct sampling is compared with electrification fusing,and experiments show that direct sampling is more stable while electrification fusing is more efficient.ZnO nanowires have cut-off properties,and good Schottky contact with the tungsten probes was established.In piezoelectric experiments,the maximum piezoelectric voltage generated by an individual ZnO nanowire was 0.07 V,and its impedance decreased with increasing input signal frequency until it became stable.This work offers a technical reference for the pick-up and construction of nanomaterials and nanogeneration technology.
基金supported by the Research Fund Program of the Guangdong Provincial Key Laboratory of Fuel Cell Technology (Grant No.FC202204).
文摘Single zinc oxide nanowires(ZnO NWs)are promising for nanogenerators because of their excellent semiconducting and piezoelectric properties,but characterizing the latter efficiently is challenging.As reported here,an electrical breakdown strategy was used to construct single ZnO NWs with a specific length.With the high operability of a nanomanipulator in a scanning electron microscope,ZnO-NW-based twoprobe and three-probe structures were constructed for fabricating AC/DC nanogenerators,respectively.For a ZnO NW,an AC output of between−15.31 mV and 5.82 mV was achieved,while for a DC nanogenerator,an output of24.3 mV was realized.Also,the three-probe structure’s output method was changed to verify the distribution of piezoelectric charges when a single ZnO NW is bent by a probe,and DC outputs of different amplitudes were achieved.This study provides a low-cost,highly convenient,and operational method for studying the AC/DC output characteristics of single NWs,which is beneficial for the further development of nanogenerators.
基金supported by the National Natural Science Foundation of China(Grant No.61973233).
文摘Nanowires have emerged as promising one-dimensional materials with which to construct various nanocircuits and nanosensors.However,measuring the electrical properties of individual nanowires directly remains challenging because of their small size,thereby hindering the comprehensive understanding of nanowire-based device performance.A crucial factor in achieving reliable electrical characterization is establishing well-determined contact conditions between the nanowire sample and the electrodes,which becomes particularly difficult for soft nanowires.Introduced here is a novel technique for measuring the conductivity of an individual nanowire with the aid of automated nanomanipulation using an atomic force microscope.In this method,two nanowire segments cut from the same silver nanowire are positioned onto a pair of gold electrodes,serving as flexible nanoprobes to establish controllable contact with the sample.By changing the contact points along the nanowire sample,conductivity measurements can be performed on different regions,thereby eliminating the influence of contact resistance by analyzing multiple current–voltage curves.Using this approach,the resistivity of a 100-nm-diameter silver nanowire is determined to be 3.49×10^(−8)Ωm.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.50135040 and 50173001).
文摘In this study, atomic force microscope (AFM) tips are used as tools to cut and manipulate carbon nanotubes on various surfaces. The lateral forces acting on AFM tips during manipulation are also recorded and analyzed from the perspective of micro-mechanics. It is found that differences in surface conditions can lead to obvious increase in micro-friction between nanotube and substrate. And also due to rehybridization, carbon nanotubes present excellent resilience when undergoing different degrees of strain. Finally, carbon nanotubes can complexly deform from elastic stage to plastic stage before complete rupture.
基金This study was supported by the Natural Sciences and Engineering Research Council of Canada,the Canada Research Chairs Program,and the Ontario Ministry of Research and Innovation via an ORF-RE grant.
文摘A scanning electron microscope(SEM)provides real-time imaging with nanometer resolution and a large scanning area,which enables the development and integration of robotic nanomanipulation systems inside a vacuum chamber to realize simultaneous imaging and direct interactions with nanoscaled samples.Emerging techniques for nanorobotic manipulation during SEM imaging enable the characterization of nanomaterials and nanostructures and the prototyping/assembly of nanodevices.This paper presents a comprehensive survey of recent advances in nanorobotic manipulation,including the development of nanomanipulation platforms,tools,changeable toolboxes,sensing units,control strategies,electron beam-induced deposition approaches,automation techniques,and nanomanipulation-enabled applications and discoveries.The limitations of the existing technologies and prospects for new technologies are also discussed.
基金This work was supported by the National Natural Science Foundation of China(Nos.11274395 and 61205165)the Program for Changjiang Scholars and Innovative Research Team in University(IRT13042)
文摘The orientation and shifting of individual carbon nanotubes are extremely important in the assembly of building blocks of nanodevices and in the development of one-dimensional materials for interdisciplinary applications.Here,we report an optical method that is capable of producing the controlled orientation and targeted shifting of single multiwalled carbon nanotubes(MWCNTs)using an optical-fiber nanotip.In a demonstration of this technique,a single MWCNT with an outer diameter of 50 nm and a length of 0.9 mm was first trapped by the nanotip using a laser beam with a wavelength of 980 nm and was then oriented and shifted along the nanotip axis as a result of the interaction of the MWCNT with the optical field output by the nanotip.Various optical powers were applied to characterize the orientation and shifting performance.The orientation and shifting of MWCNTs of various sizes were also demonstrated.
基金This work was supported by the National Natural Science Foundation of China (Grant Nos. 50075043, 50135040 and 50173001)the Doctorate Designation Fund of the Ministry of Education of China (Grant No. 2000000339).
文摘Nanomanipulation plays an important role in nanofabrication, it is also a technology necessary in exploring the secrets of nanoworld, and it thus becomes a start point to research future nanomachine. In this study, manipulation and cutting of carbon nanotubes have been conducted in order to examine whether we can move a nano-component from one site to another by using the tip of atomic force microscope (AFM). The technique may also be valuable for providing the constructive materials of nanofabrication. While exploring the method for manipulating and cutting of nanotubes, some new phenomena have been observed during the process. Results show that carbon nanotubes present a feature of deformation combining bending and distortion when subjected to large mechanical forces exerted by the tip of AFM. In special cases, long carbon nanotubes can be cut into two parts, by which we can remove the part where crystal lattice is flawed, and therefore a perfect nanocomponent can be obtained.
基金This work was supported by Canadian Institutes of Health Research via a Catalyst Grant,the Canada Research Chairs Program,the Ontario Research Funds--Research Excellence Program and the Natural Sciences and Engineering Research Council of Canada via a Strategic Projects Grant.
文摘Nanomanipulation under scanning electron microscopy(SEM)enables direct interactions of a tool with a sample.We recently developed a nanomanipulation technique for the extraction and identification of DNA contained within sub-nuclear locations of a single cell nucleus.In nanomanipulation of sub-cellular structures,a key step is to identify targets of interest through correlating fluorescence and SEM images.The DNA extraction task must be conducted with low accelerating voltages resulting in low imaging resolutions.This is imposed by the necessity of preserving the biochemical integrity of the sample.Such poor imaging conditions make the identification of nanometer-sized fiducial marks difficult.This paper presents an affine scale-invariant feature transform(ASIFT)based method for correlating SEM images and fluorescence microscopy images.The performance of the image correlation approach under different noise levels and imaging magnifications was quantitatively evaluated.The optimal mean absolute error(MAE)of correlation results is 68634 nm under standard conditions.Compared with manual correlation by skilled operators,the automated correlation approach demonstrates a speed that is higher by an order of magnitude.With the SEM-fluorescence image correlation approach,targeted DNA was successfully extracted via nanomanipulation under SEM conditions.