Researchers of Monash University have come up with a prototype sensor that could literally spell out your blood type. It is made up of a small piece of paper towel coated with water-repelling substance throughout, except the four areas in the shape of blood types A, B, AB and O. These areas are filled with antibodies that interact with specific blood antigens resulting in coagulation. As soon as you rinse the coating your blood group becomes evident as blood sticks to the paper. It can also tell if you're Rhesus positive or negative.
The project was funded by Australian Research Council (ARC) and another commercial partner. The researcher was inspired by the movie Harry Potter and the Chamber of Secrets, in which Tom Riddle's Diary answers questions by writing on paper. If hospitals could tomorrow determine blood type using this technology it might reduce the amount of time as well as money spent in doing so. This could especially be a game changer in case of disasters in which cases each and every second counts. The set up though still needs a level of expertise and scientific knowledge to tell the blood type accurately. We hope that a layman tells out his blood type one day with such a simple experiment and you may no longer need to go to labs.