Tsai Tsung-Chen, Liu Chia-Wei, Yang Ruey-Jen
Department of Engineering Science, National Cheng Kung University, Tainan 70101, Taiwan.
Micromachines (Basel). 2016 Nov 10;7(11):205. doi: 10.3390/mi7110205.
An energy conversion microchip consisting of two circular microchambers and a Nafion-filled microchannel is fabricated using standard micro-electro-mechanical systems (MEMS) techniques. When the chambers are filled with KCl solutions with different concentrations, the Nafion microchannel acts as a cation-selective membrane and results in the generation of electrical power through a reverse electrodialysis (RED) process. The current-potential characteristics of the Nafion membrane are investigated for devices with various microchannel lengths and electrolyte concentration ratios. It is shown that for a given voltage, the current and generated power increase with a reducing channel length due to a lower resistance. In addition, a maximum power density of 755 mW/m² is obtained given an electrolyte concentration ratio of 2000:1 (unit is mM). The optimal device efficiency is found to be 36% given a channel length of 1 mm and a concentration ratio of 1000:1 (mM). Finally, no enhancement of the short circuit current is observed at higher concentration ratios.
一种由两个圆形微腔和一个填充有Nafion的微通道组成的能量转换微芯片，是使用标准的微机电系统（MEMS）技术制造的。当腔室中填充有不同浓度的KCl溶液时，Nafion微通道充当阳离子选择性膜，并通过反向电渗析（RED）过程产生电能。针对具有不同微通道长度和电解质浓度比的器件，研究了Nafion膜的电流-电势特性。结果表明，对于给定的电压，由于电阻较低，电流和产生的功率会随着通道长度的减小而增加。此外，在电解质浓度比为2000:1（单位为mM）的情况下，获得了755 mW/m²的最大功率密度。在通道长度为1 mm且浓度比为1000:1（mM）的情况下，发现最佳器件效率为36%。最后，在较高浓度比下未观察到短路电流的增强。
