Using a process called vapor compression distillation, a single Slingshot can purify more than 250,000 liters of water per year, enough to satisfy the needs of about 300 people. And it can do so with any water source—sewage, seawater, chemical waste—no matter how dirty.
For communities that lack clean water, the benefit is obvious, but to realize that potential, the Slingshot needs to reach them first. Which is where Coke comes in: The company is not just a soft-drink peddler; it is arguably the largest, most sophisticated distribution system in the world. That’s important because the scale of the water crisis the world faces is unprecedented.
Water seems so abundant it’s easy to forget how many people don’t have a clean source of it. According to the World Health Organization, nearly a billion people lack ready access to safe drinking water, and hundreds of thousands die every year as a result. Many more fall terribly ill.
Plenty of water-purification tools exist, of course—chlorine tablets, reverse-osmosis plants—but they all have drawbacks. Either they’re not adequately portable; they require replacement parts that can be hard to come by; or, most vexing of all, they remove only certain kinds of impurities, leaving others to poison the unwitting.
Kamen calls the global water crisis a “Goliath” of a problem, which suggests that he is David. He offers a quick refresher on biblical lore: David, it bears remembering, defeated Goliath with a slingshot.
“In my life, nothing is ever simple or easy,” Kamen says. “I didn’t wake up one day and say, ‘Wow, there’s a global water problem. I think I’ll work on that.’ ” He’s sitting in his office in an old brick mill building by the Merrimack River in Manchester, New Hampshire. A life-size cardboard Darth Vader leans against one wall, and a wooden chair painted to resemble a seated Albert Einstein sits among a circle of leather swivel chairs. Photos of Kamen’s various helicopters (he’s had a number over the years and occasionally flies to Deka from his hilltop estate) hang on the wall while outtakes from his dad’s work as an illustrator for Mad Magazine and Tales from the Crypt decorate the hallway outside.
When we first sat down, I asked Kamen a simple question: How did you get interested in the water crisis? The answer turned into a highlights tour of his career, before he became famous or wealthy. Kamen is a natural storyteller, and his narrative unspools at high speed. Now 63, he grew up in Long Island, New York, and he ended up leaving college to start his first company, AutoSyringe, in 1976, to address a problem he’d heard about from his brother, a medical student: Certain patients needed such frequent treatment that trips to the hospital prevented them from living productive lives. Kamen’s solution was the world’s first wearable infusion pump, which administered doses of medication automatically. It was a hit, and Kamen sold AutoSyringe to Baxter International, a health-care company. He was just 30 years old.
Suddenly a millionaire, Kamen moved to Manchester and started Deka (derived from his first and last names). With a few exceptions, such as the now ubiquitous Segway, much of the company’s work has focused on medical innovations that solve lifestyle problems. One such project, begun 20-some years ago, was a machine to reinvent dialysis for patients with failing kidneys. Baxter International had built a device to do what’s called peritoneal dialysis, which involves filling the abdomen with a sterile saline solution and using the body’s own membranes to filter the blood. It’s less traumatic than hemodialysis, which requires passing blood through an external filter, but the contraption was noisy and bulky. The company asked Kamen to refine it.
We’d empty half the hospital beds in the world if we just gave people clean water.
Called HomeChoice, Kamen’s design was small enough to fit on patients’ nightstands and quiet enough that they could sleep while it worked. The machine required a lot of purified water, however—many gallons a day per patient—and that wasn’t cost-effective. Kamen’s instinct: Invent a medical-grade water purifier, so that patients could use water from their faucets as the base for their dialysis solution. He knew that existing purification systems, mostly based on filtration, weren’t exacting enough to meet his needs, so he looked to distillation. In Kamen’s eyes, distillation was magical in its simplicity. “The sun will evaporate the water out of an open latrine, and it will leave behind all of the bioburden, Cryptosporidium, and Giardia,” he says. “It will even separate the water from the arsenic and hexavalent chromium in a chemical waste site.”
As is so often the case, innovation, when it strikes, is an obvious-in-retrospect connection between seemingly disparate ideas. Kamen’s unique brand of genius is that he can recognize those connections and see their potential where others can’t.
But fitting one of the planet’s most elegant systems into a home appliance is not without its challenges. For his distillation machine to work, it would need to boil many gallons of water per hour, and that would require more energy than everything else in a typical U.S. home combined. So Kamen and his engineers exploited another basic scientific principle. To vaporize, water must get hot, and to do that, it absorbs energy. When the vapor condenses back into liquid, that energy gets released. If the team could recycle it, Kamen reasoned, they’d have a much more efficient process. They designed a “counterflow heat exchanger” that would run cool incoming liquid past superheated distilled water that had been vaporized and compressed. The difference in temperature would simultaneously cool the outgoing water and flash-boil the incoming liquid. All they would need is enough energy to get some water boiling and a little extra energy to power a compressor.
Kamen leans forward and grins as he ties the first chapter of his story together. “We said, ‘Wait, we can build a device that could take any input water, whether it’s got bioburden, organics, inorganics, chrome . . .and we can make pure water come out? We can put it in somebody’s house and make a supply of water for injection that would meet the U.S. Pharmacopeial standard, on less power than a handheld hair dryer, and we could make a thousand liters a day?’ ” Imagine how valuable that could be.
As the plan for his water purifier took shape, Kamen found himself thinking a lot about disaster relief. Whenever an earthquake or tsunami struck, aid organizations would request clean water before anything else because local supplies were tainted with sewage or chemicals. Kamen thought, “I’ve been trying to make a box small enough that you could carry it around for mobile dialysis, and it makes 250 gallons a day—that would be enough for a hundred people in a crisis.” More to the point, why not use the machine to help entire villages, or even nations, with persistent water needs?
“There are nearly a billion people in the world that get up every morning and their primary goal is to find water,” Kamen says. “Many travel great distances to find water that won’t kill them. And sadly, hundreds of thousands of times a year it does kill, mostly kids.” With Kamen’s purifier, people could just stick a hose in their dirty laundry water, a polluted river, or even their own toilet pit, and crystal-clear, microbe-free water would stream out of the machine.
The question was how to get the purifiers mass-produced and into the hands of those who needed them. Kamen started by approaching global aid organizations. Jim Scott, who works in business development for Deka, says the groups simply weren’t set up to scale the technology. “I think it’s probably very daunting if you’re an organization that doesn’t do that,” he says.
The medical and pharmaceutical companies Kamen had worked with over the years weren’t much better positioned to help. They had infrastructure in developed nations but not in the 100-odd countries where he hoped to see the technology deployed.
Frustrated, Kamen had another obvious-in-retrospect insight. “You talk to people that travel a lot and they say, ‘If there’s one thing you can buy anywhere in the world, it’s a Coke.’ You know the joke: A guy takes three weeks climbing to the top of Mount Everest; he gets to the top and buys himself a Coke. So I thought, Coke is something you drink, and they have coolers that are about the size of our machine, and they have bottling partnerships around the world. I’m going to go and try to convince them to do this.”
Coke’s response to Kamen’s unorthodox overture: Glad to hear from you, but how about doing another project first? That was in 2005, and one of the company’s challenges at the time was to develop a better soda fountain. Kamen teamed up with Nilang Patel, the former head of Coke’s research lab. Drawing from medical equipment Kamen had developed to precisely administer insulin and chemotherapy drugs, they created the Freestyle. The freestanding dispenser combines concentrated ingredients stored in small cartridges (as opposed to five-gallon bags of syrup) with carbonated water and sweeteners to create as many as 100 different drinks.
By 2009, the Freestyle was in production, and Kamen reminded Coke about the handshake deal to pursue what he was by then calling the Slingshot. In the interim, though, Coke had gotten a new CEO and chairman, Muhtar Kent. Kamen feared he’d have to “grovel and beg” for support, but, he says, “within a couple of minutes of meeting Muhtar, I realized he’s not like an accounting guy; he’s a big-picture, global thinker.
“ ‘Dean,’ he says to me, ‘if we can make the water, why can’t we do other things too?’ ” Providing clean water could be the cornerstone of what’s known as a bottom-of-the-pyramid strategy for developing markets. By providing the poorest people in the world with new technologies, services, and opportunities, a company can help lift them out of poverty and transform them into viable customers. Hence, the Ekocenter concept took shape as a companion to the water purifier, at least in some markets.
“We believe Coca-Cola’s business can only be as healthy as the community it is part of, so the well-being of the community is important to our long-term strategy,” says Derk Hendriksen, the general manager of the Ekocenter program. Notably, the company won’t directly profit from the program; each “downtown in a box” will operate as a standalone business run by a local entrepreneur, typically a woman, selected and trained by Coke. (That the soda giant enjoys an image boost in the process goes without saying.)
In 2011, Coke and Deka sent 15 Slingshots to Ghana for a six-month field test where they provided clean water to five rural schools. In fall 2013, Coke and its partners announced a goal to place up to 2,000 units (either standalone Slingshots or Ekocenters) around Africa, Asia, and Latin America by the end of 2015. “The commitment we made is to provide 500 million liters of safe drinking water to communities in need on a yearly basis,” Hendriksen says. That would translate into improving the lives of 500,000 people a year.
Kamen, being Kamen, sees the current goals of the Coke partnership as the first step toward a much larger one. “Fifty percent of all the people in the developing world suffer from waterborne pathogens,” he says. “We’d empty half the beds in all the hospitals in the world if we just gave people clean water.” The Slingshot won’t be the solution for all of those people, Kamen says, but he sees no reason not to strive for that.
One way he might extend the reach of the Slingshot is to pair it with his energy-efficient Stirling generator, another longtime passion project. Rather than by internal combustion, a Stirling engine works by expanding and contracting a gas in a closed system by heating and cooling it. The concept dates from the early 1800s but never found much practical use. The engine in Kamen’s generator requires nothing more than waste, leaves, or some other flammable material for fuel; a test unit in Bangladesh ran for six months on cow dung. Combined with a Slingshot, the Stirling generator would enable the purification of water anywhere, regardless of access to the electric grid or a bunch of solar panels on an Ekocenter.
This is crucial because many of the places that lack clean water also lack reliable electricity. Kamen has already established a relationship with NRG Energy, the same company that supplies solar panels to the Ekocenters, to discuss development. “We can bring base power to more than a billion people,” he says. That’s more than twice the number of people he could help with Slingshot alone and nearly a quarter of the global population. Of course, it would never occur to Dean Kamen to stop there.
Dean Kamen At A Glance
Education: Dropped out of college
Company: Deka Research and Development
Why you’ve heard of him: He developed the Segway, along with dozens of medical devices
Passion: He founded FIRST, which sponsors student robotics competitions. Last year, 350,000 kids (and 28,800 robots) participated globally.
How It Works: Slingshot Water Purifier
The system needs only enough energy to start the first boil, and a little more to power the compressor and pump. That’s supplied by an outlet or a solar panel; all the subsequent boiling and cooling self-perpetuates.
One: The user places a hose in any dirty water source—say, a polluted river or well—and a small pump draws the fluid into a boiling chamber. As the water reaches roughly 100°C, it turns to steam, which leaves behind any pollutants. They flow out of the chamber via a separate hose.
Two: The steam rises into a compressor, which squeezes it and thereby raises its pressure and its temperature by about 10°C more. The high-pressure vapor now has a higher boiling point, which means it can condense back into water at a temperature greater than 100°C.
Three: A counterflow heat exchanger runs the superheated water past the incoming flow of dirty water. The process heats the incoming water and cools the hot water to room temperature. That distilled water is ready to drink, while the dirty water vaporizes and begins the process all over again.
This article originally appeared in the June 2014 issue of Popular Science.
Read the rest of Popular Science’s Water Issue.