Stanford Bioengineers Create Effective Low-Tech Blood Centrifuge With 20 Cents Worth of Materials

Video screen capture. Stanford

Based on the design of a child's whirligig toy, this 'paperfuge' can separate blood components in less than two minutes, with no electricity.

In a great example of using a low-tech approach based on existing technology, in this case a classic children's toy, to overcome a barrier to improving lives and health outcomes, Stanford bioengineers have developed a low-cost and zero-electricity method of centrifuging blood samples. The 'paperfuge' developed by the team could potentially bring more precise diagnosis and treatment of diseases such as malaria, tuberculosis, and African sleeping sickness to poor regions of the world where high tech equipment is not only too expensive, but also requires a reliable electricity grid to operate.

We've previously covered other innovations in appropriate technology for off-grid health initiatives, such as the Spokefuge and the hospital equipment built by a rural doctor in Nigeria, but the paperfuge is even simpler, requiring nothing more than some paper, twine, and plastic, plus a little bit of human power. According to Stanford, the device can be constructed with about 20 cents worth of materials, and the rotational speed of the spinning device "can match centrifuges that cost from $1,000 to $5,000."

“There are more than a billion people around the world who have no infrastructure, no roads, no electricity. 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.” - Manu Prakash, assistant professor of bioengineering at Stanford and senior author on the study

The paperfuge is reportedly capable of spinning at speeds of 125,000 rpm, and can exert centrifugal forces of 30,000 Gs, which led Prakash to declare that to the best of his knowledge, "it’s the fastest spinning object driven by human power.” An application attesting to that fact has also been submitted to Guinness World Records.

The importance of a low-cost and zero-electricity centrifuge in healthcare initiatives in poor off-grid regions of the world can't be overstated, because those regions are also where diseases such as malaria, African sleeping sickness, HIV, and TB are most prevalent, and getting these types of low-cost diagnostic tools in the hands of medical personnel there can literally change people's lives. The original proof-of-concept paperfuge has been improved upon with further prototyping, with trials of the improved device in the lab showing that malaria parasites can be separated from red blood cells in just 15 minutes, and that "by spinning the sample in a capillary precoated with acridine orange dye, glowing malaria parasites could be identified by simply placing the capillary under a microscope."

Prakash and Saad Bhamla, a postdoctoral research fellow in his lab who is also an author of the resulting research paper, are currently conducting a field validation trial for malaria diagnostics using the paperfuge in collaboration with PIVOT and Institut Pasteur, which are both community-health organizations based in Madagascar.