Ion transportation control in nanofluidics through geometrically controlled nanoparticle assembly

Research interest on transportation of ion through nanoscale geometries has increased recently due to its emerging applications such as energy harvesting, biomolecule concentration/separation, water purification, chemical mixing etc. Besides of application studies using ion transportation, the fundamental research for revealing and understanding mechanism has been carried out by many research groups. However, until so far, the configuration of microplatform has relied on thin nanochannels based on silicon micromachining. In this paper, we present a new method that enables to control ion transportation with high ionic flux, which was intrinsically impossible for typical thin nanochnnels. Three dimensional nanochannel networks between two microchannels are created by geometrically controlled self-assembled nanoparticles. This assembled networks has a role as ion-selective membranes with high ionic selectivity and low fluidic resistance, which was trade-off relation heretofore. Electrical characteristics under various geometrical changes are studied and as a promising application, clean microenergy generation by reverse electrodialysis is presented using the proposed system.