Development of reversible bonding for microfluidic applications

Reversible bonding that allows repeating assembly and disassembly of microfluidic devices is very useful for a number of applications such as surface functionalization, complex cell patterning, and other biological analysis. However, reversible microfluidic devices fabricated with the current standard procedures can only be used for low-pressure applications. In this paper, we describe and characterize a reliable, flexible, and reversible bonding technique of PDMS-PDMS (Poly-dimethyl siloxane) using an oxygen plasma treatment. Effects of control parameters, such as the thickness of the PDMS layer, the duration and power of the plasma treatment, the duration and temperature of the thermal treatment on the quality of the obtained devices are investigated. An optimal set of control parameters enabling the obtained devices to work at high flow rates and pressures (500 A mu L/min and 148 kPa) has been determined. Furthermore, the disassembly/assembly process of the device can be repeated up to four times.