A fully automated chip that can immediately and reliably discover the blood type of a patient has been created by a team of the scientists from Japan's Tokyo University of Science. A user simply inserts a small amount of blood, presses a button, and waits for the results. 

The chip contains a micro-sized laboratory with various compartments in which the blood sample travellers in sequences and is processed until results are obtained. Inside the chip, the blood is diluted with a saline solution, and air bubbles are introduced to promote mixing.

The diluted blood is then transported to a homogenizer where further mixing yields a uniform solution. Portions of the homogenized to promote mixing. The diluted is then transported to a homogenizer where further mixing yields a uniform solution.

Portions of the homogenized blood solution are introduced into four different detector chambers. Two chambers contain reagents that can detect either A antigen or B antigens. A third chamber contains reagents that detect D antigens and a fourth chamber contain the only saline solution, serving as a negative control chamber in which the user should not observe any results.

This antigen-antibody reaction will cause blood type and whether the blood is positive or negative, all within 5 minutes. Blod transfusions, if performed promptly are a potentially life-saving intervention for some. However, the techniques involved are often very specialized, and the equipment is often very specialized and the equipment is often non-portable, taking over half an hour to yield results.