Figure 3. Fabrication process of the 3D microstructure of the constricted flow channel using maskless gray-scale lithography.

The devices shown are polymer microfluidic chips made using PDMS that were injection molded using photolithography and replica molding techniques. The chip mold was made using a maskless exposure system that achieved synchronous fabrication of the micropattern in the displayed images that were generated by a PC. The light images shown at right are the micropattern image of the maskless photolithography device (top) and a gray-scale exposure (bottom).