Smart Microfluidic Channels

The walls of microfludic “smart channels” are coated by responsive mixed polymer brushes with a gradient of chemical composition. The concept of the smart channels is based on switching/adaptive behavior of the mixed polymer brushes where wetting and nonwetting can be tuned upon interaction with liquids. This design of microfluidic channels brings new opportunities for manipulating the passage of liquids in the channels. The developed approach allows us to fabricate three microfluidic elements for separation, sensing, selection, and dosing microvolumes of liquids. Responsive mixed polymer brush coated smart microfluidic channels (see figure) switch between wetting and nonwetting behavior upon interaction with liquids. The channels can be open or shut depending on liquid properties (pH, solvent, nature, etc.). The walls of the channels probe the liquid and direct the flow into an appropriate channel. This approach allows for the fabrication of microfluidic devices that perform separation, sensing, selection, and dosing of microvolumes of liquids.