Patent ID: 7670561

Claim:
A micro fluidic device to be fluidly connected to liquid supply tubes for transferring to the micro fluidic device a plurality of kinds of fluids different from each other, and to a liquid discharge tube for receiving from the micro fluidic device a resultant fluid formed by mixing at least two of the kinds of fluids with each other, comprising, a micro fluidic element including supply ports for receiving respectively the kinds of fluids from the respective liquid supply tubes, a micro fluidal passage for mixing the at least two of the kinds of fluids with each other in the micro fluidal passage, and a discharge port for discharging the resultant fluid at a downstream side with respect to the micro fluidal passage, and joints attached respectively to the supply ports and discharge port so that the supply ports and discharge port are fluidly connected to the liquid supply tubes and the liquid discharge tube through the respective joints, wherein each of the joints is made of an elastomer, has an outer peripheral surface of truncated subulate shape at a front end portion of the joint to form a front surface as a top of the truncated subulate shape, and has in an inside at the front end portion of the joint, a cuneiform space including a front end overlapping the front surface as seen in a direction along which corresponding one of the liquid supply tubes and the liquid discharge tube is guided by the cuneiform space when the corresponding one of the liquid supply tubes and the liquid discharge tube is inserted into the joint so that the corresponding one of the liquid supply tubes and the liquid discharge tube is enabled to penetrate the front surface through the front end.