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Thinning air-water films stabilized by bacterial particles

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Acta Mechanica Sinica 2021年第1期37卷 27-34,I0001页

作者： Song Wu Yuehua Yang hongyuan jiang Hefei National Laboratory for Physical Science at the Microscale CAS Key Laboratory of Mechanical Behavior and Design of MaterialsDepartment of Modern MechanicsCAS Center for Excellence in Complex System MechanicsUniversity of Science and Technology of ChinaHefei230026China

The ability of particles to stabilize liquid films has broad applications in many fields,such as drug delivery,biofuel catalysis,and crude-oil *** mechanism of particles to stabilize emulsions has been widely ***,how particles affect the stability of suspension films is still ***,the dynamics of bacterial particles on free liquid films during evaporation is obtained by direct microscopic *** find that the initial concentration of the bacterial solution affects the evolution of the shapes and stabilities of liquid *** liquid film with a low bacterial concentration exhibits a drainage and rupture process similar to pure water,and bacteria would be evacuated during the evaporation of liquid ***,when the bacterial concentration is high,bacteria form a single-layer array in the center of the film and greatly enhance the stability of the liquid *** demonstrate that these two distinct film evaporation dynamics are caused by the difference in the lateral capillary force of the particles at different positions on the liquid film,which is not affected by the active motility of ***,our research reveals the critical role of bacteria concentration in stabilizing suspension liquid film.

关键词： Bacterial concentration Evaporation dynamics Film stability Lateral capillary force

Crystallization of self-propelled particles on a spherical substrate

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Applied Mathematics and Mechanics(English Edition) 2019年第10期40卷 1387-1398页

作者： Yan FANG Chen WANG hongyuan jiang CAS Key Laboratory of Mechanical Behavior and Design of Materials Hefei National Laboratory for Physical Science at the Microscale Department of Modern Mechanics University of Science and Technology of China

In this paper, we investigate the self-propelled particles confined on a spherical substrate and explore the structural and dynamic properties of self-propelled particles by controlling the packing fraction and activity. We find that these self-propelled particles freeze into the crystal with the increase in the packing fraction. We observe the pattern evolution of inevitable topological defects due to the geometric constraints of the spherical substrate. During the process of freezing, there is a transition from twelve isolated grain boundaries to the uniform distribution of defects with the increase in the self-propelled velocity. Finally, we establish a phase diagram of the freezing process. These results may deepen our understanding of active particles in complex and crowded environments.

关键词： self-prop elled particle freezing process geometric constraint defect

Control of the Dielectric Microrods Rotation in Liquid by Alternating Current Electric Field

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Chinese Journal of Mechanical Engineering 2014年第3期27卷 622-627页

作者： REN Yukun LI Bin jiang hongyuan School of Mechatronics Engineering harbin institute of technology School of Chemical Engineering & Technology harbin institute of technology The State Key Lab of Fluid Power Transmission and Control Zhejiang University

Microfluidics is a promising system for the manipulation of micro-nano particles and fluids. In this platform, alternating current （AC） electric field is usual an effective tool for the general particles control. However, traditional work paid more attention on the regular spherical particles with no obvious distinction when rotating, resulting in imprecise rotation speed calculation. In essence, non-spherical especially biocompatible particles are not only important for biology application but also significant for obtaining accurate rotating results. Hence, in this paper, SU-8, one of the most biocompatible materials was selected as the manipulation object. AC electric field is employed to rotate SU-8 microrods, in order to obtain a controllable rotation angle for both the accurate experimental results and biosensor applications. Firstly, Clausius-Mossotti（CM） factors frequency spectra with different surface conductance and medium conductivities are presented, thereby the theoretical formula is carried out, including both the torque and rotation velocity expressions of SU-8 microrods. Moreover, simulations for the electric field distribution are developed, indicating the rotating direction. Secondly, the quadrupole electrodes are used to generate rotating electric field, and the electrorotation of SU-8 microrods in different medium is carried out, showing that the particles rotate in the opposite direction of the electric field, meanwhile, the peak frequency increases with the conductivity increases. Finally, the experimental results are discussed and compared with theoretical analysis, and the comparison result shows that they have a good agreement. This work proposes an effective and controllable method to rotate microrods, showing extend application potentials in microelectronics and biosensors.

关键词： dielectric microrods electrorotation microfluidics

Continuous Separation of Multiple Size Microparticles using Alternating Current Dielectrophoresis in Microfluidic Device with Acupuncture Needle Electrodes

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Chinese Journal of Mechanical Engineering 2016年第2期29卷 325-331页

作者： TAO Ye REN Yukun YAN Hui jiang hongyuan School of Mechatronics Engineering Harbin Institute of Technology State Key Laboratory of Fluid Power Transmission and Control Zhejiang University

The need to continuously separate multiple microparticles is required for the recent development of lab-on-chip technology. Dielectrophoresis（DEP）-based separation device is extensively used in kinds of microfluidic applications. However, such conventional DEP-based device is relatively complicated and difficult for fabrication. A concise microfluidic device is presented for effective continuous separation of multiple size particle mixtures. A pair of acupuncture needle electrodes are creatively employed and embedded in a PDMS（poly-dimethylsiloxane） hurdle for generating non-uniform electric field thereby achieving a continuous DEP separation. The separation mechanism is that the incoming particle samples with different sizes experience different negative DEP（n DEP） forces and then they can be transported into different downstream outlets. The DEP characterizations of particles are calculated, and their trajectories are numerically predicted by considering the combined action of the incoming laminar flow and the n DEP force field for guiding the separation experiments. The device performance is verified by successfully separating a three-sized particle mixture, including polystyrene microspheres with diameters of 3 μm, 10 μm and 25 μm. The separation purity is below 70% when the flow rate ratio is less than 3.5 or more than 5.1, while the separation purity can be up to more than 90% when the flow rate ratio is between 3.5 and 5.1 and meanwhile ensure the voltage output falls in between 120 V and 150 V. Such simple DEP-based separation device has extensive applications in future microfluidic systems.

关键词： continuous separation of multiple size particles dielectrophoresis acupuncture needle electrodes microfluidic

ANALYSIS ON INFILTRATIVE CHARACTERISTICS OF DEFORMABLE POROUS MATAL RUBBER MATERIAL AND PARAMATERS IDENTIFICATION

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Chinese Journal of Mechanical Engineering 2005年第4期18卷 562-565页

作者： jiang hongyuan Xia Yuhong Su Daizhong Белоусов А И Department of Mechanical Engineering Harbin Institute of TechnologyHarbin 150001 China School of Computing and Technology The Nottingham Trent University Nottingham NG1 4BU UK Samara State Aerospace University Samara 443086 Russia

The effect of deformation of porous material on infiltrative performance is investigated. Based on Darcy theory and Boit principle, the Reynolds equation and mathematical expression of deformable metal rubber （MR） material under laminar flow are obtained according to the change of porosity of metal rubber. It is shown that the throttle of MR material is dependent on its porosity and diameter of metal wires. It will be of great value for the application of MR in throttle field.

关键词： Metal rubber Porous material Infiltrative coefficient Porosity Reynolds equation

STATIONARY DYNAMIC CHARACTERISTICS ANALYSIS OF NEW SQUEEZED FILM DAMPER

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Chinese Journal of Mechanical Engineering 2006年第3期19卷 442-445页

作者： jiang hongyuan ZHANG Ruihua XIA Yuhong School of Mechatronics Engineering Harbin Institute of Technology Harbin 150001 China

Recur to multi-hole and better elastic characteristics of metal rubber （MR）, a new squeezed film damper with MR （SFD/MR） throttle ring installed on the end of MR and MR damping ring installed on the radial direction of MR is implemented. Based on the D＇alembert principle, a locomotion equation and the mathematical model of stationary response of SFD/MR system is put forward. It proves that the SFD/MR has better ability to resist unbalance loads than the traditional SFD after the stationary dynamic characteristics of the traditional SFD and the new SFD/MR are researched.

关键词： Metal rubber Squeezed film damper Stationary dynamic characteristics

Analyses toward factors influencing sealing clearance of a metal rubber seal and derivation of a calculation formula

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Chinese Journal of Aeronautics 2016年第1期29卷 292-296页

作者： Yan Hui Zhao Yalei Liu jianguo jiang hongyuan School of Mechatronics Engineering Harbin Institute of Technology

Sealing clearance is a key factor for a metal rubber seal＇s sealability. The expansion coef- ficient and expansion deformation in the radial direction of metal rubber have been obtained through a thermal expansion experiment of metal rubber. The influence of the elastic modulus to the sealing clearance has been analyzed theoretically. By combining the temperature and elasticity factors of metal rubber with the elastic mechanics theory, the calculation formula of the sealing clearance has been derived, and the values of the sealing clearance and the leakage rate in certain working conditions have been calculated. Experimental results are consistent with calculation results in a high degree. The calculation formula of the sealing clearance can explain the influences of the temperature and elastic modulus factors of metal rubber on the sealing clearance. It can pro- vide guidance for the study of sealing mechanism of metal rubber seals.

关键词： Elastic mechanics theoryElastic modulus factor Metal rubber Seals Temperature factor

A vector hybrid triboelectric sensor(HTS)for motion identification via machine learning

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Nano Research 2023年第7期16卷 10120-10130页

作者： Nannan Zhou Hongrui Ao Xiaoming Chen Shan Gao hongyuan jiang School of Mechatronics Engineering Harbin Institute of TechnologyHarbin 150001China School of Control Engineering Northeastern University at QinhuangdaoQinhuangdao 066004China

Rapidly responding and cost-effective sensors played a crucial role in industrial ***,the lack of versatile strategies for identifying and classifying operating states on various practical behaviors has limited the rapid development of monitoring *** study developed a vector hybrid triboelectric sensor(HTS)with surface nanocrystalline containing triboelectric vibration and rotation units(triboelectric vibration unit(TVU),triboelectric rotation unit(TRU))capable of detecting the vibrational and rotary states of the *** synchronous detection of two sensing signals can be achieved due to the hierarchical structure as the basic unit of the HTS,which contributed to reducing the volume and spatial distribution of the *** on the voltage/current/charge(U-I-Q)signal amplitudes and phase features generated by the TVU,the vibration frequency and orientation of the device can be identified by using a double-layer neural network(D-LNN),in which the accuracy reaches 96.5%and 95.5%***,by combining logistic regression,D-LNN,and linear regression,the accuracy of the TRU for rotary classification exceeds 93.5%in practical *** this study,the great potential application of the HTS combined with the machine learning methods was successfully explored and exhibited and it might speed up the development of industrial detection in the near future.

关键词： vector triboelectric sensor surface nanocrystalline hierarchical structure sensing properties state detection machine learning

Effects of Chip Geometries on Dielectrophoresis and Electrorotation Investigation

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Chinese Journal of Mechanical Engineering 2014年第1期27卷 103-110页

作者： REN Yukun WU Hongchi FENG Guojing HOU Likai jiang hongyuan School of Mechatronics Engineering Harbin Institute of Technology State Key Laboratory of Fluid Power Transmission and Control Zhejiang University The First Affiliated Hospital Harbin Medical University

The electric fields employed for such work are generated using chips, such as planar linear interdigitated arrays or two parallel arrays. However, chip geometries usually affect the investigation of dielectrophoresis （DEP） and electrorotation （ER） significantly, and even may misdirect the theoretical prediction. In order to understand the electrodes geometries effect and provide a suitable range of parameters, three-dimensional simulations for the DEP and ER characterizations on the quadrupolar hyperbolical electrodes are carried out. Influences of the electrodes gaps, cell height, work region, energized voltage and frequencies for the DEP and ER manipulations are analyzed, and the analysis results show that the gaps of the electrodes and the cell height have enormous effects, but the work region is not so important. Moreover, depending on the theoretical analysis, ER experiments for polystyrene microspheres with the diameter of 20 ~m are carried out on two kinds of chips. The experimental results show that the microspheres rotate in the counter-field direction and the maximum rotation speed appears in the megahertz range. In addition, the experimental results are compared with the simulation results, showing that the three-dimensional simulations considering the chip geometries are more accurate than the two-dimensional predictions. This paper provides a new understanding for the theoretical predictions of DEP and ER manipulations, which decreases the difference of the theoretical and experimental results significantly, and will be significant for the lab chip research.

关键词： dielectrophoresis electrorotation chip geometries