A microfluidic static gradient generator using limited diffusuon through T-shaped narrow channels

Abstract

We have developed a poly (dimethylsiloxane) (PDMS)-cast microfluidic chip that contains a thin (cross-sectional area less than 1.0 μm2) but high aspect ratio (1:1 ~ 1:3) microchannels. Experimental results showed that the gradient of an example of test substances (sodium fluorescein) remained constant in the thin channel over a long period of time (30 minutes) by simple manual liquid handling. We aim to develop a thinner channel keeping the gradient longer time.