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non-contact to contact Transition： Direct Measurements of Interaction Forces between a Solid Probe and a Planar Air-Water Interface

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Chinese Physics Letters 2007年第10期24卷 2914-2917页

作者：吴迪王艺臻张进修 State Key Laboratory of Optoelectronic Materials and Technologies and Department of Physics Sun Yat-sen University Guangzhou 510275

The interaction force between a solid probe and a planar air-water interface is measured by using an atomic force microscope. It is demonstrated that during the approach of the probe to the air-water interface, the force curves decline all the time due to the van der Waals attraction and induces a stable profile of water surface raised. When the tip approaches very close to the water surface, force curves jump suddenly, reflecting the complex behaviour of the unstable water surface. With a theoretical analysis we conclude that before the tip touches water surface, two water profiles appear, one stable and the other unstable. Then, with further approaching, the tip touches water surface and the non-contact to contact transition occurs.

关键词： non-contact contact Transition Direct Measurements

non-contact cylindrical rotating triboelectric nanogenerator for harvesting kinetic energy from hydraulics

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Nano Research 2020年第7期13卷 1903-1907页

作者： Nan Zhang Cheng Qin Tianxing Feng Jun Li Zhirui Yang Xiupeng Sun Erjun Liang Yanchao Mao Xudong Wang MOE Key Laboratory of Materials Physics School of Physics and MicroelectronicsZhengzhou UniversityZhengzhou 450001China Department of Materials Science and Engineering University of Wisconsin-MadisonMadisonWI53706USA

Hydraulics provide a unique and widely existed mechanical energy source around us,such as in water or oil pipes,and ***,a non-contact cylindrical rotating triboelectric nanogenerator(TENG)was developed to harvest the mechanical energy from water *** of the TENG was based on the non-contact free-rotating between a curved Cu foil and a flexible nanostructured fluorinated ethylene propylene(FEP)polymer *** free-standing distance between two rotating interfaces avoided abrading of electrode *** TENG was able to effectively convert mechanical energy of the water flow into *** driven by water flow,the output voltage and current of the TENG reached 1,670 V and 13.4 uA,*** any energy storage component,the produced electricity could instantaneously power 12 white light emitting diodes(LEDs)bulbs and a digital *** non-contact rotating TENG would provide new opportunities for harvesting energy from many types of hydraulics as a self-sustainable power source for sensing,detection,and protection.

关键词： mechanical energy hydraulics triboelectric nanogenerator nanowire thin films non-contact

A non-contact flexible pyroelectric sensor for wireless physiological monitoring system

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Science China(Information Sciences) 2022年第2期65卷 162-172页

作者： Jian HE Sen LI Xiaojuan HOU Yongjun ZHOU Hao LI Min CUI Tao GUO Xiangdong WANG Jiliang MU Wenping GENG Xiujian CHOU Science and Technology on Electronic Test and Measurement Laboratory North University of China Science and Technology on Near-Surface Detection Laboratory China Institute of Sport Science

Recently, human physiological information wireless monitoring in real-time is particularly important in health analysis. As a solution, a non-contact wireless physiological monitoring system based on pyroelectric generator(Py G), whose core part consists of a wireless circuit processing module and a polyvinylidene fluoride(PVDF) film, has been successfully designed. Owing to the temperature change under the stimulation of an external heat source, the output voltage of the Py G self-powered flexible sensor increases with the heat source temperature variation in the range of 295–355 K. Furthermore, based on the natural temperature oscillation between the living body and surrounding environment, the sensor can realize human physiological information assessment, for example, temperature monitoring of the palms, fingers, respiratory heat signals from mouth or nose or non-contact spatial heat mapping recognition of finger movement via sensor array. On this basis, a portable wireless monitoring system was designed by integrating the intelligent sensor with a signal conditioning circuit, data conversion storage module, Bluetooth module,and power module. This system can acquire real-time human oral or nasal breathing signals in the personal mobile app to evaluate the physiological state of individuals. Additionally, the wireless monitoring system can be activated within 10 m, demonstrating the application of Py G sensors in remote data transmission.

关键词： non-contact pyroelectric generator human body heat environmental thermal energy wireless monitoring system

Combined Effect of Surface Tension, Gravity and van der Waals Force Induced by a non-contact Probe Tip on the Shape of Liquid Surface

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Chinese Physics Letters 2005年第8期22卷 2012-2015页

作者：刘楠白以龙夏蒙棼柯孚久 StateKeyLaboratoryofnonlinearMechanics InstituteofMechanicsChineseAcademyofSciencesBeijing100080//GraduateSchooloftheChineseAcademyofSciencesBeijing100049 StateKeyLaboratoryofnonlinearMechanics InstituteofMechanicsChineseAcademyofSciencesBeijing100080 StateKeyLaboratoryofnonlinearMechanics InstituteofMechanicsChineseAcademyofSciencesBeijing100080//DepartmentofPhysicsPekingUniversityBeijing100871 StateKeyLaboratoryofnonlinearMechanics InstituteofMechanicsChineseAcademyofSciencesBeijing100080//DepartmentofAppliedPhysicsBeijingUniversityofAerospaceandAeronauticsBeijing100083

Aiming at understanding how a liquid film on a substrate affects the atomic force microscopic image in experiments, we present an analytical representation of the shape of liquid surface under van der Waals interaction induced by a non-contact probe tip. The analytical expression shows good consistence with the corresponding numerical results. According to the expression, we find that the vertical scale of the liquid dome is mainly governed by a combination of van der Waals force, surface tension and probe tip radius, and is weekly related to gravity. However, its horizontal extension is determined by the capillary length.

关键词： AFM non-contact Surface

Test on an Optimized Cylindrical non-contact Piezoelectric Actuator

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Transactions of Nanjing University of Aeronautics and Astronautics 2017年第1期34卷 43-48页

作者： Chen Heng Chen Chao Yang Dong Wang Junshan Ge Yuyu State Key Laboratory of Mechanics and Control of Mechanical Structure Nanjing University of Aeronautics and Astronautics Nanjing 210016P.R.China China North Industries Group Corporation Nanyang 473000P.R.China

An optimization design for the cylindrical non-contact piezoelectric actuator is presented after analyzing the acoustic radiation pressure and acoustic viscous *** adding the specific microstructure on the rotor to alter the near-field sound effect and maximize the use of high intensity acoustic field induced by the stator to drive the rotor,the rotor speed is *** finite element analysis of the acoustic field induced by a variety of rotors with different structures is conducted,A prototype is manufactured,the speed-test system for the actuator is built,and the driving characteristics are *** results suggest that the rotation speed of the rotor can reach 4 167r/min,which demonstrates that the driving characteristics of cylindrical non-contact piezoelectric actuator are successfully improved using the optimization method proposed.

关键词： piezoelectric actuator microstructure finite element analysis non-contact

All-optical Quantitative Framework for Bioluminescence Tomography with non-contact Measurement

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International Journal of Automation and computing 2012年第1期9卷 72-80页

作者： Xue-Li Chen Heng Zhao Xiao-Chao Qu Duo-Fang Chen Xiao-Rui Wang Ji-Min Liang Life Sciences Research Center School of Life Sciences and Technology Xidian University Xi＇an 710071 PRC School of Technical Physics Xidian University Xi＇an 710071 PRC

In this contribution, we present an all-optical quantitative framework for bioluminescence tomography with non-contact measurement. The framework is comprised of four indispensable steps： extraction of the geometrical structures of the subject, light flux reconstruction on arbitrary surface, calibration and quantification of the surface light flux and internal bioluminescence reconstruction. In particular, the geometrical structures are retrieved using a completely optical method and captured under identical viewing conditions with the bioluminescent images. As a result, the proposed framework avoids the utilization of computed tomography or magnetic resonance imaging to provide the geometrical structures. On the basis of experimental measurements, we evaluate the performance of the proposed all-optical quantitative framework using a mouse shaped phantom. Preliminary result reveals the potential and feasibility of the proposed framework for bioluminescence tomography.

关键词： All-optical biol tomography quantitative framework non-contact surface extraction.

Deep-Hole Inner Diameter Measuring System Based on non-contact Capacitance Sensor

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Transactions of Tianjin University 2010年第6期16卷 447-451页

作者：于永新张恒王宗超常以哲 School of Computer Science and Technology Tianjin University National Institute of Metrology School of Precision Instruments and Opto-Electronics Engineering Tianjin University

A precise aperture measuring system of small deep holes with capacitance sensors is presented. Based on the working principle of non-contact capacitance sensors, influence of the edge effect of gauge head is studied, and one capacitance sensor for measuring the aperture of the small blind holes or through holes is introduced. The system is composed of one positioning device, one aperture measuring capacitance sensor, one measuring circuit, and software. This system employs visual CCD and two-dimensional mic...

关键词： deep-hole measurement non-contact CCD stepping motor precise positioning

non-contact monitoring and analysis system for tunnel surrounding rock deformation of underground engineering

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中国有色金属学会会刊：英文版 2005年第S1期15卷 96-99页

作者： YANG Song-lin, WANG Bin, JI Sheng-yue, LIU Wei-ning, SHI Hong-yun (Beijing Jiaotong University, Beijing 100044, China)

It is very important to monitor surrounding rock deformation in tunnel construction. The principle, function, development and application of the system composed of a total station and computer for monitoring and analyzing surrounding rock deformation were discussed. The new methods of two free station of 3D measurement and its mathematic adjustment mode were presented. The development of software for total station on-board and post for computer were also described. Without centering it and measuring its height, the total station controlled by the software on-board can fulfill the whole measurements to target points. Monitoring data can be processed by the post software and results of regression analysis, forecasting information of the tunnel surrounding rock deformation can be provided in time. The practical use shows that this system is practicable, highly accurate and efficient. It satisfies the needs of safety and information construction in tunnel construction of underground engineering.

关键词： tunnel construction deformation of surrounding rock total station non-contact monitoring data processing and analysis

non-contact optical characterization of negative pressure in hydrogel voids and microchannels

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Frontiers of Optoelectronics 2022年第1期15卷 113-120页

作者： Shihao Xu Xiaowei Liu Zehua Yu Kang Liu MOE Key Laboratory of Hydrodynamic Transients School of Power and Mechanical EngineeringWuhan UniversityWuhan 430072China Wuhan National Laboratory for Optoelectronics Huazhong University of Science and TechnologyWuhan 430074China

Negative pressure in water under tension,as a thermodynamic non-equilibrium state,has facilitated the emergence of inno-vative technologies on microfluidics,desalination,and thermal ***,the lack of a simple and accurate method to measure negative pressure hinders further in-depth understanding of the properties of water in such a *** this work,we propose a non-contact optical method to quantify the negative pressure in micron-sized water voids of a hydrogel film based on the microscale mechanical deformation of the hydrogel *** tested three groups of hydrogel samples with different negative pressure inside,and the obtained results fit well with the theoretical ***,we demonstrated that this method can characterize the distribution of negative pressure,and can thus provide the possibility of investigation of the flow behavior of water in negative *** results prove this technique to be a promising approach to characterization of water under tension and for investigation of its properties under negative pressure.

关键词： Hydrogel Negative pressure non-contact Optical