Visualization measurement for elucidation of evaporation enhancement mechanism on the surface of moth-eye structure matched by a refractive index

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K04224
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 19020:Thermal engineering-related
• Research Institution: Tokyo University of Science
• Principal Investigator: Satake Shin-ichi 東京理科大学, 先進工学部電子システム工学科, 教授 (90286667)
• Co-Investigator(Kenkyū-buntansha): 谷口 淳 東京理科大学, 先進工学部電子システム工学科, 教授 (40318225) ; 安藤 格士 東京理科大学, 先進工学部電子システム工学科, 准教授 (30385546)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 屈折率調整法 / ナノインプリント法 / 全反射蛍光顕微鏡 / UV硬化樹脂 / 分子動力学法

Outline of Final Research Achievements

We carried out 3-D visualization of total internal reflection fluorescence microscopy (TIRFM) to understand the three-dimensional motion of a nanoparticle on a nanosized step structure by using a refractive index-matching method with a water used as a working fluid, the step was made of an ultraviolet (UV)-curable resin, whose refractive index is the same as that of a water. Diffusion coefficient obtained by the motion of a fluorescent nanoparticle in the vicinity of the nanostep in water could be clearly captured without optical distortion. The measured diffusion coefficient along the edge of the step was larger than that across the step. Molecular dynamics simulations were also conducted to calculate the diffusion coefficients near nanosized step. The simulation results were qualitatively similar to the experimental observations.

Free Research Field

熱流体工学

Academic Significance and Societal Importance of the Research Achievements

本研究で用いる表面作製手法ではテーパー状の高アスペクト比の針状構造を容易に得ることができ，独創性が高く優位な技術であり，実在の蒸発を制御するために最適な伝熱デバイスの設計を見込むことができる。さらに計測手法も水中に限定しているため，生物医学系の計測が水を媒体する中で行われることに対して親和性が高い。UV硬化型樹脂を使用したナノインプリントリソグラフィ―を使うことで大面積・大量生産に向いていることから，シート状に印刷をするように作製が可能であり，低価格で大量生産できる可能性がある。