the present invention provides a loop - type microfluidic system , and the microfluid therein could be driven to move around the loop - channel repeatedly by the air comes from the air holes and through the driving conduits . in order to process the polymerase chain reaction , the microfluid should bear the temperature changes for three times . hence , plural temperature controllers are utilized to adjust the temperatures of the sections constituting the loop - channel . moreover , the times of cycles may be determined based on the desired times of reactions . the present invention could also increase or decrease the number of the air holes , the driving conduits and the temperature controllers to adjust the times of temperature changes according to the demands of various biochemical reactions .