Fluid device combining a parylene membrane channel with a fine surface structure and an operating magnetic probe

• Project/Area Number: 16K06195
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Intelligent mechanics/Mechanical systems
• Research Institution: Nihon University
• Principal Investigator: IMAI Satomitsu 日本大学, 理工学部, 教授 (20369953)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Project Status: Completed (Fiscal Year 2018)
• Budget Amount: ¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000); Fiscal Year 2018: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2017: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2016: ¥2,340,000 (Direct Cost: ¥1,800,000、Indirect Cost: ¥540,000)
• Keywords: 液滴搬送 / 流路膜 / パリレン / ３次元形状 / ロータス効果 / リキッドマーブル / 表面設計 / μ-TAS / マイクロピラー / 転落加速度 / 突起面積比 / 粘度 / 表面張力 / 転落角 / ころがり特性 / μTAS / 液滴 / 搬送 / マイクロ流路 / テクスチャー / 操作 / 薄膜 / マイクロ・ナノデバイス / マイクロマシン / ナノ材料 / 先端機能デバイス / 材料加工

Outline of Final Research Achievements

A microfluidic device to realize easy transportation and mechanical manipulation of minute amounts of droplets was developed. The device was composed of a membrane and channels. A method of fabricating three-dimensional thin film diaphragm (thickness: 10 μm) by MEMS process using parylene HT (for high temperature use) was developed. With regard to improving performance of liquid transportation, Lotus effect by forming fine projections on the substrate surface. Then optimization of the size, gap, and area ratio of the projections was conducted. A guideline for surface structure design was presented. The characteristics of the liquid marble rolling method were also investigated. Water repellent magnetic fine particles were used to separate the particles from the droplets by a magnetic field. In addition, it was found that rolling characteristics were improved by using fine particles. It could transport a very small droplet in diameter of 0.6 mm (0.1 μl).

Academic Significance and Societal Importance of the Research Achievements

MEMSで3次元の構造体を作ることは主要な研究テーマである．ダイアフラムはMEMSにおける主要な機械要素であり，3次元形状の膜を加工する技術は，ダイアフラムの可撓性を高めるために必要である．機械的特性に優れた高分子であるパリレン膜を用いた3次元形状の膜を作製する加工法を提案した．またこの加工法によって微細表面構造を設けることも可能で，流路に適用する場合は，ロータス効果を付与することもできる．また表面微細構造と液滴の搬送特性を検討し，表面設計の指針を示した．

Research Products

• [Journal Article] Thin-film diaphragms of cellulose nanofiber fabricated using high-concentration polar dispersion for application to MEMS actuators (2019)
  • Author(s): 今井 郷充
  • Journal Title: Sensors and Actuators (Elsevier) Volume: A 289 Pages: 134-143
  • DOI: 10.1016/j.sna.2019.01.007
  • Peer Reviewed
• [Journal Article] Rolling performance of liquid marbles enhanced by optimizing particles as digital microfluidics actuators (2018)
  • Author(s): 今井 郷充
  • Journal Title: Sensors and Actuators (Elsevier) Volume: A 274 Pages: 73-84
  • DOI: 10.1016/j.sna.2018.02.028
  • Peer Reviewed
• [Journal Article] Rolling performance of liquid marbles enhanced by optimizing particles as digital microfluidics actuators (2018)
  • Author(s): S.Imai
  • Journal Title: Sensors and Actuators, A(Physical) Volume: 274 Pages: 73-84
  • Peer Reviewed
• [Journal Article] Fabrication of three-dimensional parylene HT diaphragms using D-RIE with a Si substrate (2017)
  • Author(s): Satomitsu Imai
  • Journal Title: Sensors and Actuators Volume: 253 Pages: 146-155
  • DOI: 10.1016/j.sna.2016.11.021
  • Peer Reviewed
• [Presentation] Dynamic characteristics of micro-droplets on inclined surfaces with arrayed micro-pillars to transport droplets in microfluidics devices (2018)
  • Author(s): S. Oshima, R. Sakuma, Y. Nagashima, R. Sugiyama, Y. Hayasaka, S. Imai
  • Organizer: MNC2018 （JJAP)
  • Int'l Joint Research
• [Remarks] 研究室ホームページ
  • URL: http://www.eme.cst.nihon-u.ac.jp/imai.html