Nanotek & Expo

Biography

Biography: Daejoong Kim

Abstract

Energy harvesting technology has recently gained attraction as it enables the utilization of diverse ambient energy sources. Clean and sustainable energy generation from ambient environments is important not only for large scale systems but also for tiny electrical devices, because of the limitations of batteries or external power sources. Reverse electrodialysis (RED) is such a technique that converts electrical energy from the concentration gradient between a concentrated solution (e.g., seawater) and a diluted solution (e.g., fresh water). We experimentally investigated a RED device using two types of nanofluidic pores: nanoporous polycarbonate track-etch membranes and self-assembled nanopore networks. Highly effective cation-selective nanochannel networks are realized between two microfluidic channels with geometrically controlled in situ self-assembled nanoparticles in a cost-effective and simple way. The nano-interstices between the assembled nanoparticles have a role as collective three-dimensional nanochannel networks and they allow higher ionic flux under concentration gradients without decreasing diffusion potential, compared to standard one-dimensional nanochannels. We performed the parametric study by varying the concentration differences, the pore size, and the electrolyte types. We characterized the RED performance in terms of maximum voltage, maximum current, and maximum power. This microfluidic power generation system can be readily integrated with existing lab on a chip systems in the near future and can also be utilized to investigate nanoscale electrokinetics.