Figure 4.

(a) Schematic illustration of the T-channel. Due to laminar flow characteristics, the transportation of molecules between two streams in the channel was induced via diffusion. The two injected sample fluids have different diffusion coefficients; the asymmetry interdiffusion profile is generated in the microchannel. (b) Schematic representation of utilized microfluidic system with osmotic pump. The microchannel and osmotic pump were connected by a flexible tube and the flow is generated by the osmotic pump to generate concentration gradient profile along the microchannel.