Konishi Satoshi, Kakehi Yugo, Mori Fuminari, Bono Shinji
Department of Mechanical Engineering, College of Science and Engineering, Ritsumeikan University, Kusatsu, 525-8577, Japan.
Graduate Course of Science and Engineering, Ritsumeikan University, Kusatsu, 525-8577, Japan.
Sci Rep. 2021 Mar 29;11(1):7048. doi: 10.1038/s41598-021-86394-w.
Gallium alloy liquid metals (Galinstan) possessing fluidity, electric conductivity, and low toxicity are attractive for use in flexible devices and microfluidic devices. However, the oxide skin of Galinstan in the atmosphere adheres to the microchannel surface, preventing the transportation of Galinstan in the channel. To tackle the problem of the adhesion of Galinstan to microchannel, we introduced liquid with Galinstan into a channel with a diameter of 1000 μm. Then, we found that the cylindrical shape of the channel enabled smooth transportation of Galinstan independently of both the liquid and the channel material. The liquid introduced with Galinstan not only prevents adhesion but also improves the spatial controllability of Galinstan in the channel. We can control the position of Galinstan with 100 μm resolution using highly viscous (> 10 cSt) liquid. In addition, we combined the microchannel with patterned electrodes, fabricating a serially arranged capacitive device. The local capacitance detected by the patterned electrodes changed by more than 6% via the smooth transportation of Galinstan. The analysis results based on an equivalent circuit quantitatively agree with our experimental results. We can modulate the serially arranged capacitors using the smooth transportation of Galinstan in the channel.
具有流动性、导电性和低毒性的镓合金液态金属（镓铟锡合金）在柔性设备和微流控设备中具有应用潜力。然而，镓铟锡合金在大气中的氧化层会附着在微通道表面，阻碍其在通道内的传输。为了解决镓铟锡合金与微通道的粘附问题，我们将含有镓铟锡合金的液体引入直径为1000μm的通道中。随后，我们发现通道的圆柱形结构能够使镓铟锡合金独立于液体和通道材料实现顺畅传输。与镓铟锡合金一起引入的液体不仅能防止粘附，还能提高镓铟锡合金在通道内的空间可控性。使用高粘度（>10厘沲）液体，我们能够以100μm的分辨率控制镓铟锡合金的位置。此外，我们将微通道与图案化电极相结合，制造了一个串联排列的电容式器件。通过镓铟锡合金的顺畅传输，图案化电极检测到的局部电容变化超过6%。基于等效电路的分析结果与我们的实验结果在定量上相符。我们可以利用镓铟锡合金在通道内的顺畅传输来调制串联排列的电容器。
