Scientists at Stanford University have developed a blood centrifuge based on the children’s toy that costs only 20 US cents in materials to build, which competes with commercial lab centrifuges costing thousands of dollars. Doctors use centrifuges to process blood samples. Spinning at hundreds of thousands of RPMs (rotations per minute), the lab machines generate thousands of G’s (force of gravity) that cause the various components in blood to separate out into layers. Combined with chemical dyes and microscopes, it helps to isolate and identify microbes for diagnosis.
Lab centrifuges can cost hundreds or thousands of dollars, and most of them need electricity to work that often isn’t available in remote regions. Bioengineers developed prototypes using a blood capillary tube mounted on a paper disc. They were modeling of how the whirligig could change a pulling motion into a rotary motion. Looking at variables like disc size, string elasticity, and pulling force, they combined this with equations and came up with the result. It was a centrifuge made of 20 cents of paper, twine, and plastic that could spin at 125,000 RPM, generate 30,000 G’s, and process samples in 1.5 minutes.
This paperfuge can help identify malaria in the field within 15 minutes by spinning the sample in tubes coated with acridine orange dye, then dyed parasites became readily visible under a microscope. The video below discusses how the paperfuge works.
Source: Stanford University