Three kinds of titanium surface especially the HA surface are analyzed. Titanium was treated by 3 kinds of methods that were acid ＆ alkali, calcic solution and apathe solution. Samples were observed by optic micros...Three kinds of titanium surface especially the HA surface are analyzed. Titanium was treated by 3 kinds of methods that were acid ＆ alkali, calcic solution and apathe solution. Samples were observed by optic microscope and atomic force microscope （ AFM ） . The typical surface morphology of the acid and alkali group is little holes, and on the two HA surface the tiny protuberances is typical. The surface treated by apatite solution was smoother than the two formers. The rough surface treated with acid and alkali was propitious to Ca^＋ , P^- and proteins＇ adhesion, and the relatively smooth HA surface was of benefit to the cell adhesion.展开更多
【目的】探究温拌沥青混合料黏附机理,拓展温拌沥青与集料黏附性研究方法。【方法】使用原子力显微镜(atomic force microscope,AFM)测得分别加入Sasobit类温拌剂H01(质量分数分别为1.0%、3.0%、5.0%)和表面活性剂类温拌剂H02(质量分数...【目的】探究温拌沥青混合料黏附机理,拓展温拌沥青与集料黏附性研究方法。【方法】使用原子力显微镜(atomic force microscope,AFM)测得分别加入Sasobit类温拌剂H01(质量分数分别为1.0%、3.0%、5.0%)和表面活性剂类温拌剂H02(质量分数分别为0.3%、0.5%、0.7%)的温拌沥青试样黏附力,并经JKR(Johnson-Kendall-Roberts)模型和表面能理论将其转换为沥青表面能,计算沥青-花岗岩和沥青-玄武岩体系的无水、有水黏附功,并与水煮试验、水稳定性试验结果进行对比分析;对基于AFM测得的温拌沥青退针力曲线进行积分,得到黏附性指标G,并将其与沥青表面能进行相关性拟合。【结果】两类温拌剂的加入均降低了温拌沥青-集料体系的黏附功,温拌沥青-花岗岩体系的无水黏附功比温拌沥青-玄武岩体系的大,有水黏附功则相反;基于AFM求解得到的H01温拌沥青-玄武岩体系黏附功的变化趋势与水稳定性试验结果相同,而H02温拌沥青-玄武岩体系的则相反;黏附性指标G与沥青表面能之间具有较好的相关性。【结论】相比温拌沥青-玄武岩体系,温拌沥青-花岗岩体系更容易发生水损害;基于AFM求解沥青-玄武岩体系黏附功的方法适用于Sasobit类温拌沥青,不适用于表面活性剂类温拌沥青;本文提出的黏附性指标G为评价温拌沥青-集料体系黏附性提供了新的量化指标。展开更多
Additive manufacturing-also known as 3D printing-has attracted much attention in recent years as a powerful method for the simple and versatile fabrication of complicated three-dimensional structures.However,the curre...Additive manufacturing-also known as 3D printing-has attracted much attention in recent years as a powerful method for the simple and versatile fabrication of complicated three-dimensional structures.However,the current technology still exhibits a limitation in realizing the selective deposition and sorting of various materials contained in the same reservoir,which can contribute significantly to additive printing or manufacturing by enabling simultaneous sorting and deposition of different substances through a single nozzle.Here,we propose a dielectrophoresis(DEP)-based material-selective deposition and sorting technique using a pipette-based quartz tuning fork(QTF)-atomic force microscope(AFM) platform DEPQA and demonstrate multi-material sorting through a single nozzle in ambient conditions.We used Au and silica nanoparticles for sorting and obtained 95% accuracy for spatial separation,which confirmed the surfaceenhanced Raman spectroscopy(SERS).To validate the scheme,we also performed a simulation for the system and found qualitative agreement with the experimental results.The method that combines DEP,pipette-based AFM,and SERS may widely expand the unique capabilities of 3D printing and nano-micro patterning for multi-material patterning,materials sorting,and diverse advanced applications.展开更多
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
An experimental and statistical study was carried out to explore the effects of mechanical forces on the ends of linear double-stranded DNA (dsDNA) fragments. Mechanical force was applied onto individual DNA molecules...An experimental and statistical study was carried out to explore the effects of mechanical forces on the ends of linear double-stranded DNA (dsDNA) fragments. Mechanical force was applied onto individual DNA molecules during atomic force microscope (AFM)-based picking-up manipulation. By comparing the PCR efficiency of two DNA fragments with primers either at ends or at the inner regions, it was found that the ends of DNA fragments were damaged during picking-up process.展开更多
Scanning probe microscopy(SPM)is a branch of microscopy that forms images of surfaces using a physical probe that scans the specimen.Atomic force microscopy is one of the SPM family which is considered as a very versa...Scanning probe microscopy(SPM)is a branch of microscopy that forms images of surfaces using a physical probe that scans the specimen.Atomic force microscopy is one of the SPM family which is considered as a very versatile tool for surface imaging and measurements.A wide range of various samples can be measured regardless of being conductive,no-conductive,in vacuum,in air or in a fluid as a unique feature.One of the most challenges in atomic force microscopes(AFMs)is to evaluate the associated uncertainty during the surface measurements by AFMs.Here,an optical AFM is calibrated through the calibration of XYZ stage.The approach is to overcome difficulties experienced when trying to evaluate some uncertainty components which cannot be experimentally determined i.e.tip surface interaction forces and tip geometry.The Monte Carlo method is then used to determine the associated uncertainties due to such factors by randomly drawing the parameters according to their associated tolerances and their probability density functions(PDFs).The whole process follows supplement 2 to“the guide to the expression of the uncertainty in measurement”(GUM).The approach validated in the paper shows that the evaluated uncertainty in AFM is about 10 nm.展开更多
A fully automated atomic force microscope(AFM)is presented.The mechanical motion of the AFM stage was controlled by three steppers.The fine motion of the AFM was controlled by an MCL one-axis piezo plate.A32.768kHz cr...A fully automated atomic force microscope(AFM)is presented.The mechanical motion of the AFM stage was controlled by three steppers.The fine motion of the AFM was controlled by an MCL one-axis piezo plate.A32.768kHz crystal tuning fork(TF)was used as the transducer with a probe attached.An acoustic sensor was used to measure the interactions between the probe and the sample.An SR850lock-in amplifier was used to monitor the TF signals.An additional lock-in amplifier was used to monitor the acoustic signal.A field programmable gate array(FPGA)board was used to collect the data in automatic mode.The main controller was coded with LabVIEW,which was in charge of Z-axis scan,signal processing and data visualization.A manual mode and an automatic mode were implemented in the controller.Users can switch the two modes at any time during the operation.This AFM system showed several advantages during the test operations.It is simple,flexible and easy to use.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
DNA/octadecylamine(ODA) monolayers were transferred onto silicon substrates and the morphologies of the monolayers were investigated by Atomic Force Microscope(AFM). AFM images show that the morphologies of DNA dissol...DNA/octadecylamine(ODA) monolayers were transferred onto silicon substrates and the morphologies of the monolayers were investigated by Atomic Force Microscope(AFM). AFM images show that the morphologies of DNA dissolved in pure water are very different from those of DNA dissolved in the NaCl solution. When DNA molecules are dissovled in pure water, they will form ball-like structure in the monolayer. When the DNA molecules are dissolved in NaCl solution, they will form bunch lines. This DNA line offers a valuable template to direct the formation of unique inorganic nanomaterials.展开更多
文摘Three kinds of titanium surface especially the HA surface are analyzed. Titanium was treated by 3 kinds of methods that were acid ＆ alkali, calcic solution and apathe solution. Samples were observed by optic microscope and atomic force microscope （ AFM ） . The typical surface morphology of the acid and alkali group is little holes, and on the two HA surface the tiny protuberances is typical. The surface treated by apatite solution was smoother than the two formers. The rough surface treated with acid and alkali was propitious to Ca^＋ , P^- and proteins＇ adhesion, and the relatively smooth HA surface was of benefit to the cell adhesion.
文摘【目的】探究温拌沥青混合料黏附机理,拓展温拌沥青与集料黏附性研究方法。【方法】使用原子力显微镜(atomic force microscope,AFM)测得分别加入Sasobit类温拌剂H01(质量分数分别为1.0%、3.0%、5.0%)和表面活性剂类温拌剂H02(质量分数分别为0.3%、0.5%、0.7%)的温拌沥青试样黏附力,并经JKR(Johnson-Kendall-Roberts)模型和表面能理论将其转换为沥青表面能,计算沥青-花岗岩和沥青-玄武岩体系的无水、有水黏附功,并与水煮试验、水稳定性试验结果进行对比分析;对基于AFM测得的温拌沥青退针力曲线进行积分,得到黏附性指标G,并将其与沥青表面能进行相关性拟合。【结果】两类温拌剂的加入均降低了温拌沥青-集料体系的黏附功,温拌沥青-花岗岩体系的无水黏附功比温拌沥青-玄武岩体系的大,有水黏附功则相反;基于AFM求解得到的H01温拌沥青-玄武岩体系黏附功的变化趋势与水稳定性试验结果相同,而H02温拌沥青-玄武岩体系的则相反;黏附性指标G与沥青表面能之间具有较好的相关性。【结论】相比温拌沥青-玄武岩体系,温拌沥青-花岗岩体系更容易发生水损害;基于AFM求解沥青-玄武岩体系黏附功的方法适用于Sasobit类温拌沥青,不适用于表面活性剂类温拌沥青;本文提出的黏附性指标G为评价温拌沥青-集料体系黏附性提供了新的量化指标。
基金Open access funding provided by Shanghai Jiao Tong University。
文摘Additive manufacturing-also known as 3D printing-has attracted much attention in recent years as a powerful method for the simple and versatile fabrication of complicated three-dimensional structures.However,the current technology still exhibits a limitation in realizing the selective deposition and sorting of various materials contained in the same reservoir,which can contribute significantly to additive printing or manufacturing by enabling simultaneous sorting and deposition of different substances through a single nozzle.Here,we propose a dielectrophoresis(DEP)-based material-selective deposition and sorting technique using a pipette-based quartz tuning fork(QTF)-atomic force microscope(AFM) platform DEPQA and demonstrate multi-material sorting through a single nozzle in ambient conditions.We used Au and silica nanoparticles for sorting and obtained 95% accuracy for spatial separation,which confirmed the surfaceenhanced Raman spectroscopy(SERS).To validate the scheme,we also performed a simulation for the system and found qualitative agreement with the experimental results.The method that combines DEP,pipette-based AFM,and SERS may widely expand the unique capabilities of 3D printing and nano-micro patterning for multi-material patterning,materials sorting,and diverse advanced applications.
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Supported by the Major State Basic Research Development Program in China (No.2007CB936000)Chinese Academy of Sciences (No. KJCX2-EW-N03)National Science Foundation of China (Nos.10975175, 90923002, 21073222 and 10874198)
文摘An experimental and statistical study was carried out to explore the effects of mechanical forces on the ends of linear double-stranded DNA (dsDNA) fragments. Mechanical force was applied onto individual DNA molecules during atomic force microscope (AFM)-based picking-up manipulation. By comparing the PCR efficiency of two DNA fragments with primers either at ends or at the inner regions, it was found that the ends of DNA fragments were damaged during picking-up process.
基金National Institute of Standards(NIS),11211,Egypt。
文摘Scanning probe microscopy(SPM)is a branch of microscopy that forms images of surfaces using a physical probe that scans the specimen.Atomic force microscopy is one of the SPM family which is considered as a very versatile tool for surface imaging and measurements.A wide range of various samples can be measured regardless of being conductive,no-conductive,in vacuum,in air or in a fluid as a unique feature.One of the most challenges in atomic force microscopes(AFMs)is to evaluate the associated uncertainty during the surface measurements by AFMs.Here,an optical AFM is calibrated through the calibration of XYZ stage.The approach is to overcome difficulties experienced when trying to evaluate some uncertainty components which cannot be experimentally determined i.e.tip surface interaction forces and tip geometry.The Monte Carlo method is then used to determine the associated uncertainties due to such factors by randomly drawing the parameters according to their associated tolerances and their probability density functions(PDFs).The whole process follows supplement 2 to“the guide to the expression of the uncertainty in measurement”(GUM).The approach validated in the paper shows that the evaluated uncertainty in AFM is about 10 nm.
文摘A fully automated atomic force microscope(AFM)is presented.The mechanical motion of the AFM stage was controlled by three steppers.The fine motion of the AFM was controlled by an MCL one-axis piezo plate.A32.768kHz crystal tuning fork(TF)was used as the transducer with a probe attached.An acoustic sensor was used to measure the interactions between the probe and the sample.An SR850lock-in amplifier was used to monitor the TF signals.An additional lock-in amplifier was used to monitor the acoustic signal.A field programmable gate array(FPGA)board was used to collect the data in automatic mode.The main controller was coded with LabVIEW,which was in charge of Z-axis scan,signal processing and data visualization.A manual mode and an automatic mode were implemented in the controller.Users can switch the two modes at any time during the operation.This AFM system showed several advantages during the test operations.It is simple,flexible and easy to use.
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.
文摘DNA/octadecylamine(ODA) monolayers were transferred onto silicon substrates and the morphologies of the monolayers were investigated by Atomic Force Microscope(AFM). AFM images show that the morphologies of DNA dissolved in pure water are very different from those of DNA dissolved in the NaCl solution. When DNA molecules are dissovled in pure water, they will form ball-like structure in the monolayer. When the DNA molecules are dissolved in NaCl solution, they will form bunch lines. This DNA line offers a valuable template to direct the formation of unique inorganic nanomaterials.
