Establishment of quantitative correlation between friction and feeling of operation in sliding motion of finger

• Project/Area Number: 16K06040
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Design engineering/Machine functional elements/Tribology
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: Aoki Saiko 東京工業大学, 物質理工学院, 准教授 (30463053)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Project Status: Completed (Fiscal Year 2018)
• Budget Amount: ¥4,810,000 (Direct Cost: ¥3,700,000、Indirect Cost: ¥1,110,000); Fiscal Year 2018: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000); Fiscal Year 2017: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000); Fiscal Year 2016: ¥3,250,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥750,000)
• Keywords: 指の摩擦 / トライボロジー / 分子膜 / ストライプパターン / せん断強さ / パターンニング / 触覚 / パターニング / 人間の感覚

Outline of Final Research Achievements

In order to clarify the correlation between the friction stimulus on the finger and the feeling of operation, the finger friction measurement was performed with three dozen participants using various stripe-patterned glass surfaces with a molecular film having different widths, intervals, coverage, and orientation. Since the rate of change (ROC) in shear strength and normal load due to the sliding of the finger from the glass to the patterned surface was calculated, both ROCs depended on the coverage of the molecular film. Assuming that the shear strength of the finger and the surface is a friction stimulus to the finger and the change in load is regarded as a semi-conscious mechanical response (the feeling of operation) to the friction stimulus, the response to the stimulus was dependent not only on the ROC in shear strength but also on how to give the stimuli such as sliding speed and patterning of the molecular film.

Academic Significance and Societal Importance of the Research Achievements

ストライプ状分子膜パターン表面が指の摩擦特性に与える影響に着目し，指への摩擦刺激だけでなくその刺激に対する力学的応答は分子膜パターンの被覆率や角度などの各種因子に依存することを明らかにした．近年，タブレット端末のタッチパネルディスプレイにはテクスチャや超音波振動により触感を制御するインターフェースが適用されている中で，分子膜のパターニングにより指の摩擦と操作感を制御することが可能になれば，さらにユーザビリティに優れた機能性表面の開発が期待できる．

Research Products

• [Journal Article] Unconscious response to friction stimulus caused by the change in shear strength between a finger and striped glass surface with a self-assembled monolayer (2019)
  • Author(s): Saiko Aoki, Rina Yanagisawa
  • Journal Title: Tribology International Volume: 135 Pages: 143-151
  • DOI: 10.1016/j.triboint.2019.02.023
  • Peer Reviewed
• [Presentation] 異方性分子膜パターンを有する固体表面における指の摩擦特性と摩擦刺激に対する応答 (2018)
  • Author(s): 劉 依蒙, 青木 才子
  • Organizer: トライボロジー会議 2018秋 伊勢
• [Presentation] Mechanical Response Induced by Change in Shear Strength at the Sliding Contact between a Finger and a Molecular Layer-Coated Solid Surface (2017)
  • Author(s): Rina Yanagisawa, Yimeng Liu, Saiko Aoki
  • Organizer: 42th Leeds-Lyon Symposium on Tribology
  • Int'l Joint Research
• [Presentation] Friction Characteristics of a Finger Pad Slid on the Solid Surfaces Coated with Organic Molecular Layer with Different Pattern intervals and Width (2017)
  • Author(s): Yimeng Liu, Rina Yanagisawa, Saiko Aoki
  • Organizer: World Tribology Congress 2017
  • Int'l Joint Research
• [Presentation] Friction properties of Finger Sliding against Solid Surfaces Coated with Organic Molecular Layer with Different Pattern Width, Interval and Directions (2017)
  • Author(s): Yimeng Liu, Saiko Aoki
  • Organizer: Sustainable Tribology Conference 2017 AMAMI
  • Int'l Joint Research
• [Presentation] 分子膜被覆された固体表面における指の摩擦特性に与えるすべり速度と方向性の影響 (2016)
  • Author(s): 栁澤理奈，青木才子
  • Organizer: トライボロジー会議2016秋新潟
  • Place of Presentation: 朱鷺メッセ