Measurement and Theoretical Analysis on Nonequilibrium Ion Transport Phenomena Using Distance-Changeable Conical Electrodes

2015 Fiscal Year Final Research Report

• Project/Area Number: 26630057
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Fluid engineering
• Research Institution: Osaka University
• Principal Investigator: KAWANO Satoyuki 大阪大学, 基礎工学研究科, 教授 (00250837)
• Co-Investigator(Kenkyū-buntansha): DOI KENTARO 大阪大学, 基礎工学研究科, 准教授 (20378798)
• Project Period (FY): 2014-04-01 – 2016-03-31
• Keywords: 分子流体力学 / イオン流動 / 電流電圧特性 / 非定常問題 / 非平衡統計力学

Outline of Final Research Achievements

In this study, ion transport phenomena in micro-gaps are measured using an electrode pair which enables to change the distance less than 100 nm. By using a truncated conical electrode pair, whose gold coated surfaces have the taper angle of 5 degrees, we can continuously control the electrode distance with 87 nm resolution and measure ion transport phenomena in micro-gaps more than 1 μm. As a result, it is found that increases in the electrolyte concentration and/or electrode distance cause to extend the response time of non-equilibrium ionic current. The electrolyte concentration and electrode distance are related to the number of ions between the electrodes and the ions exposed to weak electric fields take long time to reach another equilibrium condition. This point measured by our experiments is also confirmed by the theoretical analysis.

Free Research Field

流体工学