An active microfluidic system packaging technology

This paper presents the design, fabrication, and characterization of a microfluidic system interface (MSI) technology for integration of complex microfluidic systems containing multiple functionalities. The microfluidic system interface technology provided a simple method for realizing complex arrangements of on-chip/off-chip microfluidic interconnects, integrated microvalves for fluid control, and optical windows for on-chip optical processes. The microfluidic interconnects were designed to provide one-step plug-in fluid interconnection utilizing a post assembled o-ring to ensure a tight seal. The integrated microvalves were completed when the MSI was assembled atop of the microfluidic system. The microvalves have been designed for zero dead volume with a displaced channel volume of 24 nl in the closed state. The valve was pneumatically actuated up to a valve pressure of 450 kPa. The optical windows were designed to allow for analysis operations such as infrared polymerase chain reaction and conventional fluorescence detection. A microfluidic system for genetic sample preparation was used as the test vehicle to prove the usefulness of the MSI technology with respect to complex microfluidic systems containing multiple functionalities. The miniaturized genetic sample preparation system consisted of several functional compartments including cell purification, cell separation, cell lysis, solid phase DNA extraction, polymerase chain reaction and capillary electrophoresis. Use of the MSI technology to enable integration of this complex lab-on-a-chip system in a hybrid multi-chip format was demonstrated. Additionally, functional operation of the solid phase extraction and PCR thermocycling compartments was demonstrated using the MSI.