Size-dependent electro-osmosis in a microchannel with low-permittivity, salt-free media
Journal
Applied Physics Letters
Journal Volume
97
Journal Issue
16
Date Issued
2010
Author(s)
Abstract
Electro-osmosis is the preferred transport mechanism in microfluidic systems. The electro-osmotic mobility in an aqueous solution is essentially independent of the microchannel size. However, in low-permittivity solvents, the screening effect is absent and the mobility is found to grow with the capillary radius according to our analytical theory and electro-osmotic flow experiments. Our results show that regardless of low surface charge density, electro-osmosis always occurs for long enough microchannels. Therefore, electro-osmosis provides a method for determining extremely low surface charge density associated with low-permittivity media. The implication in the response time of electronic paper is given as well. © 2010 American Institute of Physics.
SDGs
Type
journal article