Microfluidic Platforms for Gradient Generation and its Applications

Due to criticality of gradients in both chemical and biological fields, generating stable and controllable gradient concentration in microfluidics has significance such as analysis of cell migration, cancer metastasis, drug screening, chemotaxis and chemical synthesis. Integrated microfluidic chips are particularly amenable to gradient generation. Microfluidic chips functioning as concentration gradient have made great progress based on various principles. Diverse advanced microfluidic platforms have been developed as convection mixing-based gradient generators, laminar flow diffusion-based gradient generators, static diffusion-based gradient generator and geometric metering mixing-based gradient generator. In this review, we discuss recent advances and wide application of microfluidic gradient generators.