Yan, Jiwang

写真a

Affiliation

Faculty of Science and Technology, Department of Mechanical Engineering (Yagami)

Position

Professor

Related Websites

External Links

Profile Summary 【 Display / hide

  • To create new products with high added value, we are conducting R&D on high-accuracy, high-efficiency, resource-saving manufacturing technologies through micro/nanometer-scale material removal, deformation, and property control. Our recent research focuses on ultra-precision mechanical fabrication, micro-nano forming/imprinting, micro electrical machining, laser machining, laser recovery, and laser Raman spectroscopy.

Career 【 Display / hide

  • 2000.04
    -
    2001.09

    Research Associate, Tohoku University, Graduate School of Engineering

  • 2001.10
    -
    2005.03

    Associate Professor, Kitami Institute of Technology

  • 2005.04
    -
    2007.03

    Associate Professor, Tohoku University, Graduate School of Engineering

  • 2007.04
    -
    2012.03

    Associate Professor, Tohoku University, Graduate School of Engineering

  • 2012.04
    -
    Present

    Professor, Keio University, Faculty of Science and Technology

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Academic Background 【 Display / hide

  • 1991.07

    Jilin University, Faculty of Engineering, Department of Mechanical Engineering

    University, Graduated

  • 1994.03

    Jilin University, Graduate School, Division of Engineering, Department of Mechanical Engineering

    Graduate School, Completed, Master's course

  • 1996.01

    Tsinghua University, Graduate School, Division of Engineering, Department of Precision Instruments and Mechanology

    Graduate School, Withdrawal before completion, Doctoral course

  • 2000.03

    Tohoku University, Graduate School, Division of Engineering, Department of Mechatronics and Precision Engineering

    Graduate School, Completed, Doctoral course

Academic Degrees 【 Display / hide

  • Ph.D., Tohoku University, Coursework, 2000.03

 

Research Areas 【 Display / hide

  • Manufacturing Technology (Mechanical Engineering, Electrical and Electronic Engineering, Chemical Engineering) / Manufacturing and production engineering (Precision Engineering/Mechanical manufacturing)

  • Nanotechnology/Materials / Material processing and microstructure control (Material Processing/Treatment)

  • Nanotechnology/Materials / Nano/micro-systems (Micro/Nanodevice)

  • Nanotechnology/Materials / Composite materials and interfaces (Applied Physical Properties/Crystal Engineering)

Research Keywords 【 Display / hide

  • Ultraprecision machining

  • Micro/nano manufacturing

  • Laser processing

  • Electrical discharge machining

  • Nanomechanics

 

Books 【 Display / hide

  • Ultraprecision Machining and Metrology

    J. Yan, CRC Press, 2025.09,  Page: 352

    Scope: 1-352

     View Summary

    This comprehensive introduction to ultraprecision machining and metrology provides an essential foundation for students and engineers, offering an in-depth analysis of key methods, technologies, and practical applications. Ultraprecision machining is a critical enabling technology for producing high-value mechanical, optical, optoelectronic, and biomedical components with complex geometries and extreme precision. This book delivers a structured exploration of ultraprecision machining and metrology, covering essential topics such as system configuration, tooling, machining mechanism modeling, and surface characterization. Dedicated chapters on surface and subsurface metrology, as well as the machinability of both ductile and brittle materials, make it an indispensable resource for understanding machine design, manufacturing processes, and related materials science. Ideal for students and researchers, this book serves as a vital reference for those working in precision machining, MEMS, advanced manufacturing, and precision metrology.

  • Micro and Nanoscale Laser Processing of Hard Brittle Materials

    J. Yan and N. Takayama, Elsevier B.V., 2019.11,  Page: 242

    Scope: 1-242

  • Micro and Nano Fabrication Technology

    J. Yan (ed.), Springer Nature Singapore Pte Ltd., 2018.05

    Scope: 1-959

  • Comprehensive Materials Processing: Volume 1-13, Second edition

    Huang W., J. Yan , 2024.01,  Page: 180-204

    Scope: Chapter 10.08 Ultra-precision grooving technologies

     View Summary

    Fabricating microgrooves on part surfaces is a way to provide advanced functionality of the parts, which has recently increased in several fields, such as biotechnology, optics, and aerospace. Considerable progress has been achieved in groove-cutting technology with the equipment development, process optimization and mechanisms understanding. This chapter reviews the ultraprecision cutting technologies for manufacturing of microgrooves and microgroove-based microstructures on various materials. Major cutting methods and their principles/mechanisms for microgrooving have been introduced. The main challenges in the cutting of microgrooves on ductile materials and brittle materials, respectively, are pointed out. Some innovations in groove-cutting technology are also highlighted. Several aspects in demand for further research and development are provided.

  • Advanced Ceramic Coatings: Fundamentals, Manufacturing, and Classification, R. K. Gupta, A. Motallebzadeh, S. Kakooei, T. A. Nguyen, A. Behera (eds.)

    P. J. Liew, J. Yan, C. Y. Yap, Elsevier B. V., 2023.06

    Scope: Chapter 19: Electrical discharge coating with quarry dust powder suspension,  Contact page: 433-460

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Papers 【 Display / hide

  • Micromachining of Carbon Fiber Reinforced Plastics Using Femtosecond Pulsed Laser

    Konishi, Y; Yan, JW

    NANOMANUFACTURING AND METROLOGY 8 ( 1 )  2025.12

    ISSN  2520-811X

     View Summary

    Microscale grooves and holes were fabricated in carbon fiber reinforced plastics (CFRPs) using femtosecond pulsed laser irradiation, and the characteristics and mechanisms of laser processing were investigated. The relationship between laser fluence and ablation depth was established by measuring the cross-sectional profiles of the microgrooves produced at different laser fluences. Furthermore, the effect of the angle between the edge of the micro holes and the carbon fibers was examined by analyzing the edges and wall surfaces of circular and rectangular holes. Experimental results revealed that the laser processing mechanism was strongly dependent on fiber orientation due to significant heat conduction along carbon fibers. The findings of this study contribute to a deeper understanding of the ultrashort pulsed laser processing characteristics and mechanisms for creating small holes in CFRPs and emphasize the possibility of drilling high-precision holes that can be used in the direct bonding of sensors/IC chips to CFRPs.

  • Effect of System Dynamics on Surface Topography in Fast Tool Servo-Based Diamond Turning of Microlens Arrays

    Hashimoto T., Yan J.

    Nanomanufacturing and Metrology 8 ( 1 )  2025.12

    ISSN  2520811X

     View Summary

    A lens array is often used for optical components of sensing devices, requiring high surface quality and form accuracy. Fast tool servo (FTS)-based diamond turning is one of the technologies for manufacturing complicated shapes, such as freeform optics, structured surfaces, and microlens arrays, with high machining efficiency. In this study, lens array machining was performed on copper using an FTS on a diamond turning machine. For evaluating the lens array surface topography, the focus was on surface waviness formation. As a dominating factor of surface waviness, the system dynamics behavior was investigated by capturing and analyzing the position signal. It was found that a specific waviness pattern could be formed on the surface due to the servo response. By considering the dynamics of the FTS system from the captured signals, the FTS system behavior was identified, and optimal machining parameters for the lens array were proposed. A machining test under the optimized cutting conditions reduced the average Sdq used to quantify the waviness amount from 93 to 50 µrad and the standard deviation from 33 to 3 µrad, which greatly improved the consistency in accuracy for all lens arrays. This study will contribute to the appropriate utilization of FTS systems in the ultraprecision machining of various advanced optics, such as microlens arrays.

  • Fabrication of Groove-with-Protrusion Surface Structures on Oxygen-Free Copper Using a Laser-Engineered Burnishing Tool

    Otani A., Yan J.

    Nanomanufacturing and Metrology 8 ( 1 )  2025.12

    ISSN  2520811X

     View Summary

    Microtextured surfaces, such as those with groove, hole, or protrusion structures, are widely used in various industries for bonding dissimilar materials because of their anchor effect, which enhances adhesion and penetration with other materials. Although surfaces with grooves and protrusions are expected to show higher bonding strength, it is difficult to fabricate such hybrid structures using a material removal process or additive manufacturing. This study established a new burnishing method using a tool with preformed microgrooves at the tip to fabricate groove-with-protrusion structures on metal surfaces by plastic deformation. The tip of a ball-shaped polycrystalline diamond (PCD) tool was irradiated with a femtosecond pulsed laser to generate multiple trapezoid ten-micron scale grooves. Burnishing was then conducted on an oxygen-free copper surface to investigate the characteristics and mechanism of the burnishing-induced plastic deformation behaviors. The results showed that protrusions and grooves, which were several tens of micrometers in height and depth, were simultaneously produced along the tool path on the material surface. Tool sliding on the workpiece induced shear stress, which mainly triggered dislocation movement and plastic deformation enhancement. Cross-sectional observation revealed that grain elongation and refinement remarkably increased with the burnishing depth, indicating that the shear stress from burnishing produced refined grains that flowed and formed the protrusions. This research demonstrates the feasibility of a highly efficient method for simultaneously generating groove-with-protrusion structures with enhanced surface properties.

  • Laser masking enabled replication of latent fingerprints from transparent substrates

    Guo H., Qian Y., Wang X., Zhang Z., Jiang M., Huang H., Yan J.

    Vacuum 242 2025.12

    ISSN  0042207X

     View Summary

    Latent fingerprints (LFPs), though critical in forensic investigations, are often invisible and difficult to detect, especially on transparent material surfaces. Here, we present a novel nanosecond pulsed laser printing technique to replicate LFPs from transparent substrates onto metal surfaces. By placing a metal plate beneath the transparent material with the fingerprint side up, the components of the fingerprint selectively block the laser, enabling the transparent substrate to act as a photomask. This results in controlled ablation of the metal surface, replicating the fingerprint with high fidelity. Additionally, laser-induced backside etching produces a mirrored copy of the fingerprint pattern on the underside of the transparent material. Grayscale analysis confirms enhanced clarity of the printed fingerprints compared to the original LFPs. Importantly, the method is effective on curved, colored, and flexible transparent substrates and allows multiple high-quality replications from a single sample, offering a promising tool for forensic applications.

  • Simultaneous laser nitriding and biomimetic texturing: A synergistic strategy for enhancing mechanical properties and corrosion resistance of Ti6Al4V alloy

    Zhang H., Huang H., Yan J.

    Journal of Materials Processing Technology 345 2025.11

    ISSN  09240136

     View Summary

    The service reliability and lifespan of Ti6Al4V in high-end equipment application are limited by its poor wear resistance and susceptibility to pitting corrosion. Pulsed laser nitriding and simultaneous microtexturing can improve surface hardness and wear resistance. However, this method faces a mutual constraint between modified layer thickness and structural regularity. In this study, composite microtextures comprising periodic ripples and uniform vein-like structures are fabricated on Ti6Al4V by CW laser nitriding. Inspired by biological surfaces, various biomimetic textures are created, among which the biomimetic fish scale surface (BFS) exhibits remarkable performance enhancement. Its cross-section consists of a dendritic TiN layer on the surface and a dense acicular α'-Ti phase within the molten pool, with the modified layer thickness increasing to nearly 20 μm. Compared with the substrate, the cross-sectional hardness increases by 117 %, while the wear rate decreases by 10 % and 96 % under dry friction and starved lubrication, respectively. Moreover, the corrosion potential shifts positively from −579.84 mV to −299.47 mV, and the corrosion current density decreases by three orders of magnitude. The formation mechanisms of the microtextures are elucidated based on the evolution of microscopic morphologies and finite element simulations. The hardness enhancement is interpreted through analysis of the cross-sectional microstructure, whereas the improvement in corrosion resistance is revealed through impedance spectroscopy and passive film composition. This work provides a new strategy for the integrated construction of nitrided layers and functional microtextures on titanium alloy surfaces.

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Reviews, Commentaries, etc. 【 Display / hide

  • Femtosecond Pulsed Laser Machining of Fused Silica for Micro Cavities

    J. Yan

    Tool Engineers 66 ( 8 ) 83 - 87 2025.07

    Article, review, commentary, editorial, etc. (scientific journal), Single Work, Lead author

  • Laser-based micro/nano machining technologies for high-value added manufacturing

    J. Yan

    Machines and Tools 14 ( 11 ) 8 - 15 2024.11

    Article, review, commentary, editorial, etc. (scientific journal), Single Work, Lead author

  • Creating functional surfaces by micro/nano scale laser machining

    J. Yan

    Laser (Journal of the Japan Society of Laser Technology) 49 ( 1 ) 20 - 25 2024.11

    Article, review, commentary, editorial, etc. (trade magazine, newspaper, online media), Single Work

  • Laser polishing technologies for additive-manufactured metal products

    J. Yan

    Journal of the Japan Society for Abrasive Technology 67 ( 8 ) 440 - 443 2023.08

    Article, review, commentary, editorial, etc. (scientific journal), Single Work, Lead author

  • Ultraprecision ductile mode machining of hard brittle materials

    J. Yan

    Journal of the Japan Society of Mechanical Engineers 125 ( 1247 ) 11 - 14 2022.10

    Article, review, commentary, editorial, etc. (scientific journal), Single Work, Lead author, Corresponding author

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Presentations 【 Display / hide

  • Scale-bridging surface structuring for functional performance improvement of components

    J. Yan

    7th CIRP CSI Conference on Surface Integrity 2024 (ブレーメン) , 

    2024.05

    Oral presentation (keynote)

  • Tool Dynamics-induced Surface Topography Error in Fast Tool Servo-Based Diamond Turning of Micro Dome Arrays

    T. Hashimoto, J. Yan

    7th CIRP CSI Conference on Surface Integrity 2024 (Bremen) , 

    2024.05

    Oral presentation (general)

  • Influences of tool tip geometry on surface/subsurface damage formation in nanoscratching of single-crystal 4H-SiC

    W. Huang, J. Yan

    7th CIRP CSI Conference on Surface Integrity 2024 (Bremen) , 

    2024.05

    Oral presentation (general)

  • Ultraprecision manufacturing for small optics

    J. Yan

    Nanotechnology and Precision Engineering (NPE) International Series Forum (Online) , 

    2024.04

    Oral presentation (invited, special)

  • 自由曲面加工における工具姿勢に起因する切削メカニズム変化

    川上凜太朗,閻 紀旺

    精密工学会第31回学生会員卒業研究発表講演会 (東京) , 

    2024.03

    Oral presentation (general)

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Awards 【 Display / hide

  • JSME Medal for Outstanding Paper

    L. Zhang, Y. Sato, J. Yan, 2024.04, The Japan Society of Mechanical Engineers, Optimization of fast tool servo diamond turning for enhancing geometrical accuracy and surface quality of freeform optics

    Type of Award: Award from Japanese society, conference, symposium, etc.

  • IJEM Best Editor Award

    J. Yan, 2024.01, International Journal of Extreme Manufacturing (IJEM), IoP publishing

    Type of Award: Honored in official journal of a scientific society, scientific journal

  • JSPE Best Paper Award

    Lin Zhang, Allen Yi, J. Yan, 2023.03, The Japan Society for Precision Engineering, Flexible fabrication of Fresnel micro-lens array by off-spindle-axis diamond turning and precision glass molding

    Type of Award: Award from Japanese society, conference, symposium, etc.

  • 2022 IJEM Best Paper Award

    Y. Sato, J. Yan, 2023.03, International Journal of Extreme Manufacturing (IJEM), IoP publishing, Tool path generation and optimization for freeform surface diamond turning based on an independently controlled fast tool servo

    Type of Award: Honored in official journal of a scientific society, scientific journal

  • Machine Tool Technology Promotion Award

    S. Kasai, T. Sodetai, J. Yan, 2021.06, 工作機械技術振興財団, 炭素拡散反応を用いた形彫り放電加工による多結晶ダイヤモンドの3次元形状創製

    Type of Award: Award from publisher, newspaper, foundation, etc.

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Courses Taught 【 Display / hide

  • ULTRAPRECISION MACHINING AND METROLOGY

    2025

  • SPECIAL LECTURE SERIES ON MULTIDISCIPLINARY AND DESIGN SCIENCE

    2025

  • LABORATORIES IN SCIENCE AND TECHNOLOGY

    2025

  • INDEPENDENT STUDY ON INTEGRATED DESIGN ENGINEERING

    2025

  • INDEPENDENT STUDIES IN MECHANICAL ENGINEERING

    2025

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Memberships in Academic Societies 【 Display / hide

  • The Japan Society of Mechanical Engineers, 

    1997.04
    -
    Present
  • The Japan Society for Precision Engineering, 

    1997.04
    -
    Present
  • The Japan Society for Abrasive Technology, 

    2000.04
    -
    Present
  • Japan Society for Laser Technology (JSLT), 

    2022.01
    -
    Present
  • Japan Laser Processing Society (JLPS), 

    2009.01
    -
    Present

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Committee Experiences 【 Display / hide

  • 2025.03
    -
    Present

    Fellow, Society of Manufacturing Engineers (SME)

  • 2024.08
    -
    Present

    Fellow, The International Academy for Production Engineering (CIRP)

  • 2024.04
    -
    Present

    Fellow (foreign), The Engineering Academy of Japan (EAJ)

  • 2022.04
    -
    Present

    Fellow, The International Society for Nanomanufacturing (ISNM)

  • 2022.03
    -
    Present

    Director, Executive Director, Chairman of Publication Sector, Chairman of Journal Review Board, Japan Society of Precision Engineering (JSPE)

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