A centrifuge costing 20 cents based on a toy


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On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.

 
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"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs." --San Antonio Express-News

Scientists at Stanford have developed a centrifuge costing 20 cents to make, based on a child’s toy, that can be used in the field to separate blood samples.

According to Stanford, Prakash and post-doctoral fellow Saad Bhamla came up with the “paperfuge” while looking at toys like tops and yo-yos for inspiration. Noticing how the disc of a whirligig spins when the cords on either side are pulled, they decided to make a slow motion video of one, only to discover that it rotated at 10,000 to 15,000 RPM.

The pair started developing prototypes using a blood capillary tube mounted on a paper disc, but they went beyond simple tinkering as they recruited three undergraduate engineering students from MIT and Stanford to create mathematical models 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 from the physics of supercoiling DNA to gain a better understanding of the whirligig’s mechanism.

The result was a centrifuge made of 20 cents of paper, twine, and plastic that could spin at 125,000 RPM, generate 3,000 G’s, and process samples in 1.5 minutes.

I have embedded a video explaining the paperfuge below the fold. I wonder if a variation of this on ISS could do low gravity experiments.

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