In this paper,the force-distance curves have been employed to investigate the force sensing properties of the probe-type microforce sensors.In the preliminary studies,two kinds of probe-type microforce sensors have be...In this paper,the force-distance curves have been employed to investigate the force sensing properties of the probe-type microforce sensors.In the preliminary studies,two kinds of probe-type microforce sensors have been used to load the objects with dry and wetted surfaces.One is a developed piezoresistive cantilever force sensor with sensitivity of 35 μN/V and the other an atomic force microscope(AFM) cantilever beam probe with sensitivity of 10.4 nN/V.The force outputs corresponding to the regimes of approaching,indenting,and loading are obtained,and the properties of the stability in the approaching regime of the sensors,local mechanical behavior of the tested objects in the indenting regime,and the force sensing of the global samples are analyzed.Experimental results of this analysis are also presented.展开更多
Atomic force microscopy （AFM） has the advantage of obtaining mechanical properties as well as topographic information at the same time. By analyzing force-distance curves measured over two-dimensional area using Her...Atomic force microscopy （AFM） has the advantage of obtaining mechanical properties as well as topographic information at the same time. By analyzing force-distance curves measured over two-dimensional area using Hertzian contact mechanics, Young＇s modulus mapping was obtained with nanometer-scale resolution. Furthermore, the sample deformation by the force exerted was also estimated from the force-distance curve analyses. We could thus reconstruct a real topographic image by incorporating apparent topographic image with deformation image. We applied this method to carbon black reinforced natural rubber to obtain Young＇s modulus distribution image together with reconstructed real topographic image. Then we were able to recognize three regions; rubber matrix, carbon black （or bound rubber） and intermediate regions. Though the existence of these regions had been investigated by pulsed nuclear magnetic resonance, this paper would be the first to report on the quantitative evaluation of the interfacial region in real space.展开更多
In the tapping-mode atomic force microscope(TM-AFM),the probe tip continuously taps the sample surface,which may cause plastic deformation of the sample and result in energy dissipation.The energy dissipation of the p...In the tapping-mode atomic force microscope(TM-AFM),the probe tip continuously taps the sample surface,which may cause plastic deformation of the sample and result in energy dissipation.The energy dissipation of the probe is closely related to the scanned phase image.To quantify the energy dissipation due to plastic indentations of the sample,this study utilized a combination of molecular dynamics(MD)simulations and experiments on single-crystal copper samples,including multiple nano-indentation tests.The energy dissipation of the probe due to the plastic deformation of the sample was calculated by integrating the hysteresis curve of the indentation depth versus the force applied to the indenter.The simulation results are in good agreement with the experimental ones.Both sets of results have demonstrated that the plastic energy dissipation decreases as the number of indentations increases,and eventually the energy of the probe tends to stabilize.This equilibrium energy dissipation is associated with other dissipation mechanisms.Furthermore,it was observed that,after hundreds of taps,the dissipated energy of plastic deformation could be ignored,implying that the scanned image may not reflect the plasticity information of the sample after multiple taps of the probe on the sample surface for scanning.展开更多
Nano-mechanical mapping by atomic force microscopy has been developed as an useful application to measure mechanical properties of soft materials at nanometer scale.To date,the Hertzian theory was used for analyzing f...Nano-mechanical mapping by atomic force microscopy has been developed as an useful application to measure mechanical properties of soft materials at nanometer scale.To date,the Hertzian theory was used for analyzing force- distance curves as the simplest model among several contact mechanics between elastic bodies.However,the preexisting methods based on this theory do not consider the adhesive interaction in principle,which cannot be neglected in the ambient condition.A new analytical method was introduced...展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos 10972113 and 10732080)the National Basic Research Program of China (Grant Nos 2007CB936803 and 2010CB631005)SRFDP (Grant No 20070003053)
文摘In this paper,the force-distance curves have been employed to investigate the force sensing properties of the probe-type microforce sensors.In the preliminary studies,two kinds of probe-type microforce sensors have been used to load the objects with dry and wetted surfaces.One is a developed piezoresistive cantilever force sensor with sensitivity of 35 μN/V and the other an atomic force microscope(AFM) cantilever beam probe with sensitivity of 10.4 nN/V.The force outputs corresponding to the regimes of approaching,indenting,and loading are obtained,and the properties of the stability in the approaching regime of the sensors,local mechanical behavior of the tested objects in the indenting regime,and the force sensing of the global samples are analyzed.Experimental results of this analysis are also presented.
文摘Atomic force microscopy （AFM） has the advantage of obtaining mechanical properties as well as topographic information at the same time. By analyzing force-distance curves measured over two-dimensional area using Hertzian contact mechanics, Young＇s modulus mapping was obtained with nanometer-scale resolution. Furthermore, the sample deformation by the force exerted was also estimated from the force-distance curve analyses. We could thus reconstruct a real topographic image by incorporating apparent topographic image with deformation image. We applied this method to carbon black reinforced natural rubber to obtain Young＇s modulus distribution image together with reconstructed real topographic image. Then we were able to recognize three regions; rubber matrix, carbon black （or bound rubber） and intermediate regions. Though the existence of these regions had been investigated by pulsed nuclear magnetic resonance, this paper would be the first to report on the quantitative evaluation of the interfacial region in real space.
基金support from the National Natural Science Foundation of China(NSFC 11572031).
文摘In the tapping-mode atomic force microscope(TM-AFM),the probe tip continuously taps the sample surface,which may cause plastic deformation of the sample and result in energy dissipation.The energy dissipation of the probe is closely related to the scanned phase image.To quantify the energy dissipation due to plastic indentations of the sample,this study utilized a combination of molecular dynamics(MD)simulations and experiments on single-crystal copper samples,including multiple nano-indentation tests.The energy dissipation of the probe due to the plastic deformation of the sample was calculated by integrating the hysteresis curve of the indentation depth versus the force applied to the indenter.The simulation results are in good agreement with the experimental ones.Both sets of results have demonstrated that the plastic energy dissipation decreases as the number of indentations increases,and eventually the energy of the probe tends to stabilize.This equilibrium energy dissipation is associated with other dissipation mechanisms.Furthermore,it was observed that,after hundreds of taps,the dissipated energy of plastic deformation could be ignored,implying that the scanned image may not reflect the plasticity information of the sample after multiple taps of the probe on the sample surface for scanning.
基金the financial support from National Institute of Advanced Industrial Science and Technology (AIST),Japan Chemical Innovation Institute (JCII) and New Energy Development Organization (NEDO) as one of the projects in the Nanotechnology Program by the Ministry of Economy,Trade,and Industry (METI) of Japan.
文摘Nano-mechanical mapping by atomic force microscopy has been developed as an useful application to measure mechanical properties of soft materials at nanometer scale.To date,the Hertzian theory was used for analyzing force- distance curves as the simplest model among several contact mechanics between elastic bodies.However,the preexisting methods based on this theory do not consider the adhesive interaction in principle,which cannot be neglected in the ambient condition.A new analytical method was introduced...
