Local, Affordable, and Sustainable Technologies

High-tech engineers create low-tech improvements to life in the developing world

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This podcast is part of the Sustainable Design radio program, a collaboration between IEEE Spectrum and the National Science Foundation.

Susan Hassler: On a smaller scale, let’s consider some practical and simple technologies that can improve lives, and sometimes save them. Steven Cherry tells us about products that can help the 40 percent of the world’s people who live on less than $2 a day.

Steven Cherry: Basic necessities, like water and energy, can’t be shipped from the first world to the third. We need local, affordable, and sustainable solutions.

[Running water]

Steven Cherry: Clean water is the most basic need of all, yet almost a billion people don’t have a ready source of it. Simple bacteria in dirty water kills 1.5 million children each year—more than AIDS, malaria, and measles combined. But now, for about a dollar, you can generate 18 000 liters of water. Yes, 18 000. The LifeStraw, developed by Vestergaard Frandsen, a Swiss company, looks like an inch-and-a-half thick straw. It contains a special halogen-based resin fiber that lets you filter water by pouring it through the straw, or just stick the LifeStraw directly into a pool of water, even if it’s full of mud and bacteria and viruses, which it kills as effectively as if you’d boiled the water for 20 minutes.

[Electrical snap; then a fizzle. Voice: “Awwwww.”]

Steven Cherry: More than a billion of the world’s people don’t have electricity, not even simple reading lights. Denmark’s Risø National Laboratory for Sustainable Energy has found a cheap way to integrate light-emitting diodes, photovoltaic cells, and ultrathin lithium batteries into a simple plastic sheet that can be used as a lamp. You lay the sheet flat during the day, let it soak up the sun’s rays, and then roll it back into a cylinder shape at night. You plug one side into the other to complete the circuit, and voilà! You have enough light to read by.

[Lamp switch sound. Voice: “Ahhhh!”]

Steven Cherry: And now, eyeglasses. Sure, eyeglasses don’t seem very high tech, until you think about all the equipment at the eye doctor’s office. In half the world—the developed half—there’s one optometrist for every four or five thousand people. But in places like sub-Saharan Africa, the ratio is about a million to one. So Josh Silver, a professor of physics at Oxford University, has come up with an eye lens that’s filled with fluid and connected to a tiny syringe. You turn a dial until there’s just the right amount of fluid to create the right prescription for your eyes.

At the other end of the body, there’s the Jaipur Foot, from India. It’s been refined over and over again since its first development in the 1960s and now uses simple waterproof plastics so that a below-the-knee prosthesis costs less than $50. With it, recipients can walk comfortably, ride a bicycle, run, jump, dance, and even climb a tree.

These are just a few of the many ways 21st-century high-tech engineers are coming up with low-tech, sustainable improvements to life in the third world. I’m Steven Cherry.

This podcast is part of the Sustainable Design radio program, a collaboration between IEEE Spectrum and the National Science Foundation.