Fabrication of three-dimensional microfluidic systems

Abstract

In microfluidic devices, three-dimensional microstructures that can be applied to more diverse fields were fabricated by PDMS molding technique that is based on conventional soft lithography technology. Very thin patterned membrane was fabricated and integrated to bulk PDMS structures by bonding after oxidizing the surfaces of PDMS structures. For the application where collection of fluid is necessary, fabrication of a larger chamber in micro systems was realized. The system cannot be made by conventional photolithography. PDMS passive valve was also fabricated. Because the structure of valve is very simple, it is easy to fabricate. And the performance was tested by integrating the valve with electro magnetic actuation source. The flow rate was measured at the frequency of 0.1, 0.5, 1, 2, 3, 4 and 5 Hz. Although the passive valve could not give perfect one way flow, the performance was satisfactory.