KEIO RESEARCHERS INFORMATION SYSTEM

Profile Summary 【 Display / hide 】

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 】

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 】

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 】

Academic Degrees 【 Display / hide 】

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

Research Areas 【 Display / hide 】

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 】

Research Keywords 【 Display / hide 】

• Ultraprecision machining

• Micro/nano manufacturing

• Laser processing

• Electrical discharge machining

• Nanomechanics

Books 【 Display / hide 】

Books 【 Display / hide 】

• Ultraprecision Machining and Metrology

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

  Scope: 1-352

• 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.

  • Access to Document (DOI)

• 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 】

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.

  • Access to Document (DOI)

• 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.

  • Access to Document (DOI)

• 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.

  • Access to Document (DOI)

• Fabrication of convex and concave microstructures on Ti6Al4V via nanosecond laser texturing and their distinct effects on surface wettability

  Wang C., Li L., Huang H., Yan J.

  Journal of Manufacturing Processes 152   616 - 630 2025.10

  ISSN  15266125

  　View Summary

  Precise control of surface microstructures is crucial for the functional design of advanced materials, particularly in applications such as superhydrophobic surfaces. However, current laser micro/nano fabrication techniques still face a persistent “easy-concave, hard-convex” challenge, where concave structures (e.g., microcraters and grooves) are readily produced but the fabrication of convex structures (e.g., micropillars, bulges) remains difficult. Consequently, the underlying mechanisms governing the functional difference between convex and concave structures are still not clear. In this study, both convex and concave microstructures were successfully fabricated on Ti6Al4V surfaces by optimizing the parameter window of nanosecond laser irradiation. The evolution of surface morphology under various laser parameters was systematically explored, and the formation mechanisms were clarified through the coupling effects of Marangoni convection and recoil pressure. Convex and concave arrays with varying hatch distances were fabricated and subjected to annealing treatment for comparatively studying their difference in wettability. After annealing, concave structures consistently exhibited superhydrophobicity, whereas convex structures demonstrated hydrophobicity or superhydrophobicity depending on the hatch distance. The mechanism underlying the difference in wettability was further revealed by analyzing the surface morphology and chemical composition. Furthermore, lossless liquid transportation was successfully realized by utilizing the adhesion difference between the convex and concave structures. This study not only offers a novel approach for constructing microstructures on titanium alloy surfaces but also provides new insights into the functional difference between convex and concave structures.

  • Access to Document (DOI)

• Towards understanding the ultrasonic vibration-assisted diamond cutting of ZnO crystals: Surface integrity and tool wear mechanism

  Huang W., Hashimoto T., Yan J.

  Journal of Materials Processing Technology 344 2025.10

  ISSN  09240136

  　View Summary

  Zinc oxide (ZnO) is a promising material for optics and optoelectronics. However, its machining methods are limited, with polishing being virtually the only available technique, which restricts the fabrication of complex shapes. In this study, for the first time, ultraprecision diamond cutting of single-crystal ZnO was explored. Conventional cutting (CC) and ultrasonic vibration-assisted cutting (UVC) experiments were performed in dry and oil mist lubrication environments. It was found that under dry conditions, both CC and UVC resulted in surface fractures owing to the oxidation-induced chemical tool wear. Using oil mist lubrication significantly reduced tool wear, particularly for UVC. As a result, surface roughness was reduced to 1.9 nm Sa. Cutting in the [11−20] direction was more likely to achieve crack-free surfaces on ZnO than cutting in the [1−100] direction under CC; however, the machinability in cutting in the [1−100] direction was improved by applying UVC. Both CC and UVC processes activated basal and pyramidal slip systems in the subsurface region, accompanied by a high density of dislocations located immediately beneath the surface. UVC further promotes polycrystallization and pyramidal slip activity in the subsurface. A microlens array was fabricated with a surface form error of less than 49 nm peak-to-valley and a surface roughness of less than 2.2 nm Sq by integrating slow tool servo diamond turning with ultrasonic vibration assistance under oil mist lubrication. This study reveals the fundamental cutting characteristics of ZnO, provides guidance for ultraprecision cutting of brittle oxide crystals, and validates a potential solution for fabricating micro-structures on ZnO surfaces.

  • Access to Document (DOI)

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Reviews, Commentaries, etc. 【 Display / hide 】

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 】

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 】

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 】

Courses Taught 【 Display / hide 】

• INDEPENDENT STUDIES IN MECHANICAL ENGINEERING

  2025

• GRADUATE RESEARCH ON INTEGRATED DESIGN ENGINEERING 2

  2025

• GRADUATE RESEARCH ON INTEGRATED DESIGN ENGINEERING 1

  2025

• FUNDAMENTAL OF MANUFACTURING

  2025

• FACTORY VISITING

  2025

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Memberships in Academic Societies 【 Display / hide 】

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 】

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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