Indian American Manu Prakash innovates medical use for ancient paper toy whirligig

Prakash puts the high manual-rotations of whirligig to separate blood plasma from red blood cells (RBCs).

Stanford professor Manu Prakash’s lab developed a 20-cent centrifuge based on an ancient spinning toy. Credit: Kurt Hickman/Stanford News Service.

An Indian American professor at the Stanford University has developed a centrifuge based on the technique of whirligig – a disc with two threads passing from the center. Manu Prakash used the spinning speed of the circular disc to separate blood plasma from red blood cells (RBCs).

“To the best of my knowledge, it’s the fastest spinning object driven by human power,” Prakash, who completed his B.Tech from the Indian Institute of Technology, told Stanford News.

Prakash’s equipment works manually. They put a small plastic capillary tubes on the circular disc. When someone pulls the strings from both ends, the disc completes up to 125,000 rotations per minute. The rotational movement helps to separate the blood and indicators of malaria, tuberculosis, sleeping sickness and HIV.

The idea of testing whirligig first came from Prakash’s colleague Saad Bhamla. A research fellow in bioengineering, Bhamla, too, hails from India and completed his Bachelor of Technology from Indian Institute of Technology, Madras. Bhamla recalled the toy from his childhood games in India. Initially, Bhamla himself recorded the rotations of the homemade whirligig from threat and a button. While analyzing the footage he realized that it was spinning between 10,000 and 15,000 revolutions per minute (rpms). “I remember feeling that this was it, this was what we’d been looking for.” Bhamla told Wired.

Prakash and Bhamla immediately put students at the Massachusetts Institute of Technology and Stanford University in California to check what makes the whirligigs spin so fast. The team found that the strings wind so tightly that they store the extra energy by recoiling. This helps to increase the speed of the disc attached with the strings.

“To the best of my knowledge, it’s the fastest spinning object driven by human power,” Prakash said. His simple but innovative observation has come out handy for medical practitioners. Apart from saving money, centrifuge machines can cost $5,000 whereas Prakash’s technology costs barely 20 cents, this technique sounds more effective, too. Prakash calls his piece of technology “Paperfuge” after centrifuge.

“There are more than a billion people around the world who have no infrastructure, no roads, no   electricity,” Prakash said. “I realized that if we wanted to solve a critical problem like malaria diagnosis, we needed to design a human-powered centrifuge that costs less than a cup of coffee.”

Bhamla told Wired that he initially thought that people would rather laugh at the insignificant-looking piece of technology, but he was wrong. “The first people we met with, I thought they would laugh at me when I showed it to them,” Bhamla said. He said that he remember a woman tell him “you don’t understand it like I do. I have been looking for something like this for years.”

Prakash’s new technology would revolutionize the lab testing techniques and enable people to carry centrifuges, weighing barely 2 grams, in their pockets to the most difficult regions.

The John D. and Catherine T. MacArthur Foundation said, while announcing the five-year, $625,000 grant, that bioengineer’s work is “driven by curiosity about the diversity of life forms on our planet and how they work, empathy for problems in resource-poor settings, and a deep interest in democratizing the experience and joy of science globally.”

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