Manu Prakash is scaling down microscopes to expand their global reach

Staining a layer of onion skin with iodine and visualising its cells under the microscope is an overused classroom experiment for some. But when Professor Manu Prakash was growing up in the small Indian town of Ranpur, neither he nor any of his classmates had ever laid eyes on a microscope. Their science practical exams involved sketching the instrument from memory of textbook diagrams.

This didn’t deter Prakash’s curiosity about the world around him. “We could explore nature,” he says. “We’d leave home in the morning and only return at night.” The young adventurer went on to study computer science at the Indian Institute of Technology in Kanpur before moving to Massachusetts Institute of Technology for a PhD in applied physics.

Today, as an engineer at Stanford University, Prakash develops affordable and portable microscopes that can be distributed to remote and low-income communities. His goal is to make education opportunities more equitable and to improve the diagnosis of diseases in hard-to-reach locations.

Fashioning microscopes out of paper

Lab-grade microscopes that cost hundreds of thousands of dollars to purchase and maintain are out of reach for people living in under-resourced communities. So, Prakash set his team at Stanford a challenge to invent a microscope that costs no more than $1 to build. Instead of using plastics and metals, he and his colleagues fashioned an “origami” microscope made out of paper. They named it FoldScope.

The magnifying lens posed the biggest hurdle. Most microscopes use very thin glass lens to focus light and magnify an image, but these often come with a four-figure price tag. Prakash’s team had to find a suitable alternative made of thick glass, which causes undesirable warping of the microscopic image. They opted to use a glass ball as the lens.

“That’s the hidden magic of FoldScope,” Prakash says. Its spherical shape only distorts the image at the edges of the view, but anyone peering through the centre can see features down to an individual cell. “There’s a sense of disbelief, still today, when people build a FoldScope,” says Prakash, adding that they don’t believe they’ll see single bacteria swimming around right in front of their eyes.

There’s a sense of disbelief, still today, when people build a FoldScope.

When Prakash’s laboratory published their invention in 2014, many in the scientific community maintained some level of doubt about its potential, he says. It dawned on Prakash that the existence of this microscope was not enough. “What truly matters is that this object gets in the hands of millions.”

He put out an announcement that his team was prepared to ship FoldScope to anyone in the world who asked for it. “We literally built an entire factory inside the lab to manufacture them,” he says, and his team shipped out approximately 100,000 microscopes free of charge. This self-funded operation baffled many, he says, because the team wasn’t focused on exploring specific scientific questions—their goal was to democratise tools for scientific exploration. “We were saying, ‘Here are the scientific tools. Explore your world,’” says Prakash.

FoldScope’s impact is felt far and wide. People in remote places use it to diagnose a range of parasites like schistosomiasis, an acute and chronic disease caused by parasitic worms. It’s being used to detect fungal infections that affect rice crops, and to catch cervical cancers early. FoldScope also fills in for bulky, expensive microscopes in classrooms.

Charting microbial life in the oceans

With the origami microscope blazing a trail, Prakash began exploring new frontiers. A research expedition at sea to study aquatic microbes, like plankton, revealed to him how intractable these creatures are to scientists. A single expedition cost tens of thousands of dollars per day, he discovered, making it impossible to monitor how climate change and pollution impact microscopic life across the oceans.

So began the development of PlanktoScope—a portable microscope that seafarers could use out on the open ocean to monitor microscopic life on a global scale. This time, Prakash’s team had to compromise on price to build a more advanced instrument, but they still limited themselves to parts that cost no more than $1000, making their system relatively affordable.

Hundreds of PlanktoScopes around the world feed data about aquatic microbes into an open database where researchers can study planetwide trends. These instruments have even made their way under ice in Antarctica and the Arctic—previous blind spots for marine biologists.

Next-generation frugal instruments

FoldScope serves as an affordable alternative to simple microscopes and an educational tool. But now, Prakash’s team have taken to developing other easy-to-assemble, portable microscopes with a flurry of imaging options that could broaden the research capabilities of less well-funded laboratories and healthcare facilities. These systems, a multi-sample scanner called Squid and a microscope called Octopi, as a nod to “brainy” cephalopods, can carry out the same functions as FoldScope, such as detecting parasites. However, they can also be used to screen the effects of drugs on cells and track patterns of fluorescently labelled cellular components.

Healthcare workers, even in developed countries, usually detect Plasmodium falciparum, a parasite that causes malaria, using older diagnostic tools developed more than century ago. Since then, researchers have struggled to develop new diagnostics that are faster and equally accurate than the gold standard. With the help of artificial intelligence, Octopi can rapidly screen millions of red blood cells for the parasite, yielding a diagnosis in mere minutes. Costing no more than US$500 to produce, this system could one day expand diagnostic options for malaria and other diseases, such as sleeping sickness and tuberculosis.

When he’s not developing adaptable technologies, Prakash teaches others how to do it. His Frugal Science course at Stanford University allows students to team up with people around the globe to design tools that democratize scientific enquiry. He does this because he believes that access to science is a human right.

It’s far more important to me to enable people to explore their own curiosity.

Prakash says anyone, whether they’re professional researchers or curious citizens, can make valuable contributions to a scientific challenge, but financial barriers often get in the way of progress. He hopes for a future where science is accessible to all, where one’s imagination is their only limitation. He says, “we want to remove this barrier to tools as one of the criteria in who gets to do science.”

Story by Kamal Nahas