Generating 2-dimensional concentration gradients of biomolecules using a simple microfluidic design.

This study reports a microfluidic device for generating 2-dimensional concentration gradients of biomolecules along the width and length of a chamber and conventional 1-dimensional gradients along the width of its lateral parallel channels. The gradient profile can be precisely controlled by the applied flow rate. The proposed design is simple and straightforward, has a small footprint size compared to previously reported devices such as tree-shape designs, and for the first time, provides capability of generating desired 2D and 1D gradients, simultaneously. The finite element simulation analysis proves the feasibility of the microfluidic device, and the fluorescently labelled IgG antibody is used to demonstrate generated chemical gradients. This simple microfluidic device can be implemented for a wide range of high-throughput concentration gradient applications such as chemotaxis, drug screening, and organs-on-chips.