Abstract
Micro-fluidic devices using nonlinear electro-kinetic phenomena (NEKP) are important for promising biomedical applications such as a lab-on-a-chip and micro-total-analysis systems (μTAS). This is because NEKP produce a large flow velocity (~mm/s) with a small voltage (~V) with simple structures and can prevent the occurrence of dc problems such as chemical reactions in an electrolytic solution. In this review, we explain the basis of linear and nonlinear electro-kinetic phenomena, and introduce micro-fluidic devices using NEKP mainly from our studies. We also discuss fundamental problems on an electro-double layer based on our recent discovery on the exact solution of steady PoissonNernst-Planck equations for large applied voltages.