**5. Conclusion**

Membrane processes have been widely used in various industries for water and gas treatment. Pressure-driven membrane processes for water treatment are typically categorized by their rejection ability into MF, UF, NF, and RO. Biofouling on the membrane surface is the most severe fouling among all fouling phenomena including colloidal fouling, scaling, and organic material fouling. The dynamic behavior and viscoelastic nature of biofouling make it more complicated. Hence, it is very important to observe the real-time phenomenon that is occurring during biofouling. Microfluidic devices have therefore become essential tools to study the biological growth in a flow regime. Integrating membranes with microfluidic devices has become very popular over the past decade. There are several ways to incorporate membrane into the microfluidic device. The commercial membrane can be bonded to the device directly, or the membrane can be fabricated as a part of a fabrication process. Microfluidic devices equipped with membranes have been widely used in the medical application to study the complex permeability of macromolecular, drug or other protein. Such devices have recently used to study the fouling phenomenon in porous media. In this chapter, a thorough literature review was also provided about the microfluidic membrane filtration for biofouling study.
