Thermally actuated microfluidic system for lab on chip applications

In this paper, we present the design and fabrication of Polydimethylsiloxane based Lab-on-Chip system useful for polymerase chain reaction (PCR) application. The proposed system is fabricated on glass substrate, taking advantage of thermally conductive and electrically insulating substrate. On one side of glass microfluidic system having reaction chamber for PCR, microchannel for fluid handling and two thermally actuated valves for fluid control has been made. On the other side of glass three thin film heaters are integrated, two heaters located under valves actuate the valves membrane and allow the chamber isolation and the middle heater is dedicated to PCR thermal cycle. The design of the system, carried out by using COMSOL Multiphysics, involved the optimization of the system dimensions and the shape of microchannel used to completely close the channel. We have also study the thermal interaction between three heaters and optimize the design to minimize the interference. The system was fabricated and an experiment actuating the valves was performed verifying the closing of the microfluidic channel.