Ask inventor and entrepreneur Dean Kamen what he does for a living, and he'll tell you his job is to just be himself.
"If I'm awake, I'm working on things that matter to me," he said. "I switch between them for the variety and for the inspiration, but if you asked me which one is work and which one of them is hobby, I don't know how to separate them."
Kamen is always thinking. Thinking about the more than 150 patents he holds in the United States and Europe. Thinking about his First program -- For Inspiration and Recognition of Science and Technology -- which aims to get some of the tens of thousands of kids who participate in it excited about science and technology. Thinking about ways his company, DEKA Research and Development, can innovate.
"The definition of innovation to me is something that changes either our understanding of the world or the way we are able to run our lives and achieve a set of goals that is so significant that it is broadly adopted," Kamen explained. "That's an innovation and those are the kinds of things you dream about being able to accomplish."
A college dropout, Kamen makes a clear distinction between inventions and innovations. While innovations are rare, he said, inventions are abundant.
"In my lifetime, my earliest patents had numbers that started with a 'three' -- '3 million' something," he said. "In the relatively brief time I've been patenting things, we're up to 7 million things. That says there have been more inventions done since I started inventing than in the history of invention.
"Trust me, there haven't been more innovations."
But that hasn't kept Kamen and the engineers and fellow inventors at DEKA from trying.
Right now DEKA, located in New Hampshire, is at work on a scalable "box" based on the Stirling cycle engine, which can purify water from virtually any source and create enough electricity to power a small village.
Kamen's goal is to bring clean drinking water and power to the roughly 20 percent of the world he says lives without it.
"We try to look at what are the really big issues," he explained, "and are there technologies out there that if properly combined and coordinated could address those really big issues in a way that's likely to create an innovation."
Using the Stirling cycle engine -- an engine created in the 1800s that was considered a "safer" alternative to the steam engine at the time -- Kamen hopes to bring the Third World into the 21st century.
"Essentially [it's] a box the size of a dorm room refrigerator that requires no consumable components, that on the power of about the third of a hand-held hair dryer can produce 1,000 liters of pure water a day, enough for 100 people," he explained.
DEKA tried out two boxes in two villages in Bangladesh for about six months and just shipped two to Honduras to see how they'd work in the real world.
Because of Kamen's admittedly insatiable appetite for his work, even a trip to the local shopping mall can yield life-changing inspiration.
"I get in a car and show up at the local mall, a nice, new modern facility, and as I'm walking in out of this big flat parking lot into the mall I see a guy in a wheelchair," he recalled. "Not a frail, delicate, doddering old person, but a guy that probably was a vet and lost one of his legs so you and I could sit around suckin' down doughnuts."
Kamen says he watched as the man tried to navigate his way out of the parking lot and into the mall but hit a brick wall when he tried to find a way over the curb.
"I'm thinking, 'So we've got the technology to put guys on the moon, under the oceans ... but a full-grown adult, a pretty healthy-looking guy sitting in a wheelchair, can't get into a mall?'" he asked.
After seeing the same man a few times around the mall, Kamen realized something: The loss of mobility was one thing, but the loss of dignity was far more severe.
While picking up his nightly dinner -- "a coffee ice-cream cone" -- in the mall's food court, Kamen saw the man at a food counter struggling to be seen by the clerks on the other side.
At virtually every store, Kamen saw that the man was looking up at things he couldn't reach and that the world seemed almost inaccessible.
"If a human being was a sack of potatoes, you could throw 'em in a wheelbarrow and move 'em around," he said. "But a human being is not a sack of potatoes and mobility is not the only thing you lose when you lose is the human capability to stand up.
"You lose the ability to look your peers or your spouse in the eye. You lose the ability to interact with people over a counter or to take something off a shelf or get into a mall. Every curb and every flight of stairs might as well be the bars on the door of a jail, and I just said, 'This can't be right.'"
So Kamen started thinking about what makes human mobility, communication and lifestyle possible: balance.
"It's a very difficult skill," he said. "Ask your mother -- as a baby, there are probably only two things she remembers: your first steps and your first words. Because being able to stand up and balance and get around is a big deal."
With that in mind, Kamen got to work on what would become one of his proudest endeavors -- the Independence Ibot Mobility System, a wheelchair that can climb stairs and traverse uneven terrain, and uses a self-balancing system that can prop the chair up on two wheels, allowing the user a chance to see the world at eye level.
Instead of trying to just build another wheelchair, Kamen wanted to give back what he believes is really lost when someone loses the ability to walk.
"It took a lot of years to learn how to balance -- I mean, there's a reason kids take a long time to learn how to stand up and get around," he said. "But we did it, and we built the Ibot and virtually every disabled person I've ever seen get into it gets emotional about being able to stand up. It's a really big deal."
The work done on the Ibot led to the Segway scooter, which uses similar technology to balance a rider on two wheels.
When Dean Kamen was growing up, he had little taste for school.
As a high school student, he found himself not looking for the right answers but instead, looking for the answers he thought the teachers liked best.
That turned him off to school and -- assuming work was more of the same -- kept him from working for anyone but himself.
Although Kamen attended Worcester Polytechnic Institute, he didn't graduate. Instead, he used his access to the academic community to get his business off the ground.
"I just don't like being constrained and I frankly don't like other people arbitrarily judging what I do or telling me what to do or how to do it," said Kamen. "I always felt I'd rather do something on my own, and if I fail, OK, I'll learn, and if I succeed, I'll change the game, but I'd rather let history judge what I did, not a textbook."
Despite Kamen's less-than-stellar academic performance, he's a big proponent of education and his First program.
"It's impacting what these kids do with their time and adjusts their expectations of what their career opportunities are," he explained. "It creates relationships between kids and professional engineers that they literally could not have imagined six weeks before this."
First's goal is to make science, math, engineering and technology "cool," something Kamen believes is important in turning these fields into attractive ones for the nation's youth.
"There isn't a kid [who participates in First] who doesn't believe that science and engineering and technology isn't every bit as fun and rewarding or accessible as sports or entertainment," he said, "which were the only two fields where they could see public role models in our culture."
During last year's program alone, more than 70,000 students participated in First.
Whether meeting former President Clinton, attending one of the First regional championships, pulling another day at the office or just taking his Segway for a ride, Dean Kamen's signature bluejeans and dress shirt say a lot about the man behind the creations.
"People always say to me, 'Why do you always wear jeans,'" he said. "I say, 'I don't always wear jeans! If I'm sleeping, I'm not wearing jeans, if I was in a swimming pool, I wouldn't be wearing jeans.'"
"I just wear jeans because that's what I wear when I'm working. But if I'm awake, I'm working, so that's what I wear."