研究内容 – Yan Laboratory, Keio Univ.

研究ポリシー

kawakami — Sat, 20 Jul 2024 14:00:30 +0000

To achieve the production of higher value-added products, our laboratory is advancing the proposal of high-precision, high-efficiency, energy-saving, and resource-conserving processing technologies based on material removal, deformation, and property control in the micro and nano domains, as well as elucidating the principles behind them.
Innovation through Multidisciplinary Integration
Yan laboratory aims to achieve optimal processing tailored to material properties by combining various methods such as machining, laser processing, and electrical discharge machining. We also possess state-of-the-art equipment to support a wide range of interdisciplinary research.
Mechanical Processing
Electrical Processing
Laser Processing
Research Facilities
Social Contribution through Industry-Academia Collaboration
Our laboratory emphasizes industry-academia collaboration in order to develop cutting-edge manufacturing technologies that address societal demands and contribute to real-world applications through partnerships with relevant companies. Each researcher tackles themes related to societal issues and actively presents their work at domestic and international conferences, as well as in academic journals.
A Global, Multicultural Lab Environment
Our laboratory actively welcomes international students from various regions, fostering a vibrant research environment where students from diverse cultural backgrounds communicate beyond language barriers. This not only creates an enriching lab experience but also nurtures individuals who can excel on the global stage.
Interview Videos and Articles

機械加工

reasend — Sat, 20 Jul 2024 13:00:39 +0000

ナノオーダーレベルの超精密加工を駆使した、機能性・付加価値の創造。
Ultra-precision machining is vital in semiconductor and optical industries, demanding high accuracy. We specialize in cutting challenging brittle materials and creating free-form surfaces using advanced equipment like Fast Tool Servo (FTS) for industrial applications.
Ultra-precision cutting of freeform surfaces
近年カメラや測定機の性能向上に伴い、光学性能を高める有効な手段として自由曲面レンズの利用が注目されています。閻研究室では、非軸対称の形状を加工可能な最新の5軸旋削加工機を用いて、様々な材料・加工条件におけるナノメートル精度の自由曲面加工を研究しています。
Ultra-precision grinding of hard and brittle materials
Demand for brittle materials such as silicon and glass as lens materials has been increasing in recent years. Brittle materials pose significant challenges in machining, yet the demand for heightened form accuracy escalates annually. Consequently, cutting techniques capable of achieving nano-scale surface finishes are critically important, offering a promising approach to attaining superior machining accuracy. We have been researching suitable machining parameters for various brittle materials and have succeeded in high-precision machining.
Ultrasonic vibration assisted machining
Ultrasonic vibration-assisted cutting (UVC) is a technique that enhances the cutting process by superimposing high-frequency vibrations on the cutting tool. This vibration causes periodic intermittent cutting, altering the material removal mechanism compared to conventional cutting. As a result, UVC offers several advantages, including reduced cutting forces, minimized tool wear, and improved surface finish of the machined workpiece. UVC is particularly effective in machining difficult-to-cut materials, such as hardened steels and glass, and is widely used in precision manufacturing applications. By combining slow-tool-servo and ultrasonic vibration-assisted cutting, Yan lab has achieved free-form surfaces with nanometer surface roughness on high entropy alloys using diamond tools.

レーザー加工

reasend — Sat, 20 Jul 2024 12:00:39 +0000

レーザによる精密加工が、産業の新たな可能性の扉を開く。
Laser processing has attracted widespread attention for its high precision and flexible characteristics , offering innovative possibilities for industry. We are researching methods to generate functional microstructures to influence the surface properties of materials using various laser processing.
3D microfabrication
Scanning with ultrashort laser pulses enables high-precision processing with minimal thermal damage to the material and reduces burrs and cracks. We are attempting to create new surface functions by forming specific patterns of microscale holes, grooves, and nano-periodic surface microgroove structures on the surfaces of difficult-to-machine materials like single crystalline materials, ceramics, and hard brittle materials such as cemented carbides.
Laser repair of machining-affected layers
Even in nanoscale ultra-precision machining, a machining-affected layer inevitably forms on the surface of the workpiece. In our laboratory, we propose a laser repair technique that uses nanosecond pulsed laser irradiation to selectively melt only the machining-affected layer at a nanosecond scale. Subsequently, liquid-phase epitaxial crystal growth is initiated using the dislocation-free bulk region as a seed. This technique allows us to rapidly obtain a single-crystal surface to effected layer free and crack free surface.
Nanomaterial creation
We are developing and evaluating nanocomposite materials with entirely new functionalities by binding and structurally controlling nanomaterials such as nanoparticles, nanofibers, nanotubes, and nanosheets using laser or infrared irradiation. For example, we have succeeded in developing high-capacity, long-life next-generation lithium-ion battery silicon anodes by forming nanoparticles through pulse laser irradiation of waste silicon powder generated in large quantities during the production processes of semiconductor devices and solar cells.

電気加工

reasend — Sat, 20 Jul 2024 11:00:39 +0000

Support the development of industry by improving the technology of electrical machining.
Precision machining, surface modification, and microfabrication of complex three-dimensional features on hard materials. In Yan laboratory, we are researching combining electrical discharge machining with other electro-mechanical processes to improve the functionality of widely used industrial materials like steel, tungsten carbide, silicon carbide, and polycrystalline diamond.
Electrical discharge machining
Precision machining, surface modification, and microfabrication of complex three-dimensional features on hard materials. In Yan laboratory, we are researching combining electrical discharge machining with other electro-mechanical processes to improve the functionality of widely used industrial materials like steel, tungsten carbide, silicon carbide, and polycrystalline diamond.
Composite machining
放電加工は、銅や真鍮のような安価で展性のある電極材料を用いて、硬い脆性材料に複雑な形状を加工することが可能であり、費用対効果の高い微細加工プロセスと言えます。ナノオーダーの表面加工は難しく、研磨などの後処理が必要ですが、後追い加工を行うと工具のアライメント誤差の発生が問題となります。
閻研究室では、研削加工や電解加工などの仕上げ加工を放電加工と同じ工具で行うことで、アライメント誤差を防ぐ「一機複合加工」を研究し、高い加工効率の精密加工を実現しました。
Electrical discharge coating
Surface defects such as fracture and cracks have become a problem for mechanical parts due to high temperature, high pressure, and long-term use. In Yan Laboratory, we are studying a coating technique called electrical discharge deposition. In electrical discharge machining (EDM), the tool electrode material is machined so that it does not wear away, and electrical discharge coating (EDC) aims to improve surface defects by depositing the tool electrode material on the surface of the workpiece. It also aims to add new functionality, such as wear resistance, by devising the material on the tool electrode side.

研究設備

reasend — Sat, 20 Jul 2024 10:00:38 +0000

Cutting-edge research with the latest equipment.
In the Yan Laboratory, there are numerous machining and measurement instruments available for advanced research.
Let's work together to conduct cutting-edge research using the latest machinery.
Machining equipment
Cutting machine
3-axis CNC ultraprecision machine tool
4-axis CNC ultraprecision machine tool
5-axis CNC ultraprecision machine tool
Relevant machines
Nanoform X / Fast-Tool-Servo / Kistler
Ultra sonic / Micro probe
Laser processing machine
Micro-second pulse laser
Nano-second pulse laser
Pico-second pulse laser
Femto-second pulse laser
Electrical discharge machine
3-axis micro EDM machine
Die-sinking EDM machine
Measuring instrument
White light interferometer
Laser microscope
Laser-probe ultraprecision surface profiling system
Nanoindentation tester
Chromatic aberration confocal non-contact probe