WEI ZHENG头像

WEI ZHENG

Associate professor

Research direction:

Education: Doctor of Philosophy

  • Department: College of Mechanical and Electrical Engineering
  • ORCID:
  • DBLP:

10 Access

  • Email: weizheng@mail.buct.edu.cn
  • Office : 412 Mechanical Engineering Building

Introduction

Born in March 1970, he holds a Ph.D. in Science and is currently an associate professor. He graduated from the School of Engineering Mechanics at Chongqing University in 1993 and worked at the 11th Research Institute of the 067 Base in the Aerospace Industry from 1993 to 1998. In 2001, he completed a Master’s degree in Solid Mechanics at Beijing Jiaotong University and subsequently began a Ph.D. in Mechanics at the Institute of Mechanics, Chinese Academy of Sciences. During his doctoral studies, he served as a visiting scholar at the Hong Kong University of Science and Technology from 2004 to 2005. In July 2006, he joined Beijing University of Chemical Technology. Later, from May 2013 to May 2014, he was a visiting scholar at the Technical University of Darmstadt, Germany.

Education

Work Experience

Social Position

Social Activities

Research

Research area

1) Effect of microscale adhesion contact and liquid bridge on contact hysteresis

The team has been extensively engaged in theoretical and experimental research on micro- and nano-contact mechanics, with an experimental platform primarily centered on AFM. Our work includes in-depth theoretical analysis of adhesive contact and energy dissipation in micro- and nanocontact mechanics, as well as scratch, friction, and wear experiments on carbon nanotube-reinforced polymers using AFM and other nanoindentation tools. Through these studies, we have proposed corresponding enhancement mechanisms.

We have also experimentally investigated the velocity effects on AFM force measurements under atmospheric conditions, arriving at conclusions that differ from those found in vacuum environments. Additionally, we conducted both experimental and theoretical analyses on the formation of liquid bridges near the AFM needle tip, drawing significant attention from scholars worldwide upon publication. This work sparked international debate, with European and American scholars discussing the mechanism of liquid bridge formation. Notably, one side of the debate referenced two of the applicant's papers to support their arguments, specifically regarding the time-dependent nature of AFM liquid bridge formation. Professor Butt, the director of the Max Planck Institute for Polymer Research and an international authority on AFM in Germany, has cited the applicant’s experimental and theoretical contributions multiple times. Relevant publications are available in the applicant's profile.

2) Dynamic processes of liquid bridge generation and breakage and their effects on AFM imaging

The problem is first analyzed and explored theoretically, with particular attention to contact issues occurring on the microsecond scale. This involves calculating the characteristic times for three key mechanisms of liquid bridge formation. For the experimental study of liquid bridge dynamics, a swept-frequency approach is employed. Liquid bridges are a significant cause of image distortion in atomic force microscopy (AFM) under atmospheric conditions and contribute substantially to adhesion in such environments. Thus, understanding liquid bridge dynamics is essential for insights into imaging mechanisms and sample properties.

Effect of Ambient Humidity on AFM Scanning Morphology

In terms of theory, this investigation centers on the relationship between capillary forces and probe-sample distance, examining how fracture energy varies with relative humidity and contact angle. By integrating the liquid bridge into a vibrational model, vibration theory is applied to identify variations in the height and phase of probe samples under constant excitation amplitude. Experimentally, sample surfaces are prepared with gradient contact angles, and humidity levels are adjusted to capture height and phase images at each setting, allowing for direct comparison with theoretical predictions.Study of Pressure Film Damping on AFM Vibration Characteristics

When the AFM operates in tapping mode, the effect of air pressure film damping becomes more pronounced as the probe tip approaches the sample. To investigate how pressure film damping influences the AFM’s vibrational system, frequency-sweeping experiments are conducted using a pinless tip probe and a microsphere tip probe, respectively. Using vibration theory, these experiments provide simplified models of system stiffness for both probes. The microsphere tip vibration model is further reduced to a one-dimensional oscillator, allowing for an in-depth analysis of the impact of pressure film damping. Findings confirm that the air pressure film damping model accurately captures microscale interactions between the probe and sample, offering valuable insights into tapping mode dynamics in AFM.

Research projects hosted

  1. Beijing University of Chemical Technology Young Teachers' Fund (Project No. QN0716), July 2007 - June 2009: Research on Adhesion Problems at Micro- and Nano-Scale.

  2. Open Fund of Beijing Key Laboratory of New Polymer Materials Preparation and Processing, January 2008 - January 2009: Experimental Study on the Interaction between Nanomaterials and Rubber.

  3. National Natural Science Foundation of China (NSFC) (Grant No. 11072024), January 2010 - December 2013: Influence of Liquid Bridges on Adhesive Contact Hysteresis at Micro- and Nano-Scale.

  4. National Defense Military Project (Project No. JG201103), November 2011 - December 2012: Experimental Study on the Deformation of Underground Caverns in XXXXXX.
  5. National Natural Science Foundation of China (NSFC) (Grant No. 11572031), January 2016 - December 2019: Study on the Effect of Humidity and its Mechanism in Atomic Force Microscopy Topography Measurement.

  6. Open Fund of the State Key Laboratory of Nonlinear Mechanics, January 2017: Effect of Humidity on Vibration Characteristics of Micro-Cantilever Beams in Atomic Force Microscopy.
  7. Enterprise Technology R&D Project (Project No. H2020390), November 2020 - June 2022: Research on the Working Performance of Hall Thruster.



 







Teaching

As the Director of the Basic Mechanics Teaching and Research Department at the School of Electromechanical Engineering, Beijing University of Chemical Technology, he teaches undergraduate courses in theoretical mechanics, mechanics of materials, engineering mechanics, and mechanical fundamentals, as well as a postgraduate course in vibrational mechanics. Over the past three years, he has conducted 584 hours of classroom instruction, averaging 195 hours per year.

He has led several teaching reform initiatives, including:

  1. Undergraduate Training Program for Basic Mechanics (2020-2022).

  2. University-Level High-Quality Online Open Course in Finite Element Methods (2018-2020).

In addition, he has organized and mentored both undergraduate and postgraduate students for the National Zhou Peiyuan Undergraduate Mechanics Competition, achieving the Excellence Award (Individual Competition) in the 12th competition.


Postgraduates

Funding

Vertical Project

Horizontal Project

Publications

Two papers in JCR1 region of Chinese Academy of Sciences, one paper in CiteScore partition 1 region, the paper has 241 SCI citations, the highest single citation 109 times, the highest single citation 33 times in the last 3 years.

  1. Wei Z, Zhao Ya-Pu. Adhesion elastic contact and hysteresis effect. Chinese Physics, 13(8): 1320-1325(2004).

  2. Wei Z , Zhao Ya-Pu. Experimental investigation of the velocity effect on adhesion forces with an atomic force microscope. Chinese Physics Letters,21(4): 616-619 (2004).

  3. Wei Z, Zhao Ya-Pu, Ruan S.L., Gao P and Yu T.X.  A study of tribological behavior of carbon nanotubes reinforced ultrahigh molecular weight polyethylene composites. 

  4. Wei Z, Zhao Ya-Pu. Growth of liquid bridge in AFM. Journal of Physics DApplied Physics,40:4368-4375(2007)

  5. Wei Z, He M F and Zhao Y P. The effect of surface roughness on adhesion hysteresis. Journal of Adhesion Science and Technology 24:1045-1054(2010)
  6. Wei Z, He M F and Zhao Y P. Thermodynamic analysis of liquid bridge for fixed volume in atomic force microscope, Sci China Phys Mech Astron, 56: 1962-1969(2013) 

  7. Wei Z, Wang Z R, Sun Y, et al. Dissipation Energy in Tapping-Mode Atomic Force Microscopes Caused by Liquid Bridge. Chinese Physics Letters, 35(1):016802(2018)

  8. Wei Z ,Sun Y ,Ding W X ,et al. The formation of liquid bridge in different operating modes of AFM. Science China Physics Mechanics & Astronomy, 59(9):694611(2016)

  9. 魏征,陈少勇,赵爽,孙岩.原子力显微镜中等容液桥的毛细力分析.应用数学和力学,35:364-376(2014)

  10. 魏征赵爽陈少勇丁文璇.原子力显微镜中液桥生成机理探讨.应用数学和力学, 35:87-98(2015).

  11. 魏征,孙岩,王再冉,.轻敲模式下原子力显微镜的能量耗散.力学学报, 49(6):1301-1311(2017).

  12. 丁文璇,刘运鸿,魏征.原子力显微镜探针振动的简化模型分析[J].力学与实践, 39(5):449-454(2017).

  13. 魏征,孙岩,王再冉,.轻敲模式下原子力显微镜的能量耗散.力学学报, 49(006):1301-1311(2017).

  14. 柳世华,魏征(通讯作者).压膜阻尼对原子力显微镜振动特性的影响研究.振动与冲击,39(11):185-191(2020)

  15. 刘运鸿,郑骁挺,魏征.轻敲模式原子力显微镜相位,频移特性研究[J].机械设计与制造工程, 49(2):97-100(2020).

  16. 魏征,郑骁挺,刘晶.轻敲模式下AFM动力学模型及能量耗散机理研究.力学学报,


 

 

 

 


Awards

Patent

Honor Reward

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