Of the many things people take for granted – particularly in Western society – clean water is at the top of the list. Not only do we expect it to flow limitlessly at the turn of a faucet, we also – to put it politely – routinely contaminate clean water every time we use a toilet. Yet for the better part of a billion people, simply finding enough clean water to drink is a daily challenge. A full 50 percent of all human illness is the result of contaminated water.

For the past 15 years, inventor Dean Kamen has been acutely aware of this immense challenge, making it his mission to develop a water-purification equivalent of the slingshot in the famous biblical tale of David and Goliath.

The documentary SlingShot tells the story of how Kamen – the inventor of the Segway – became so obsessed with solving the world's water crisis that he poured an immense amount of effort – and millions of his own dollars – into creating a device that can extract pure water from putrid water.

Kamen's SlingShot makes it just as easy to clean a tank of soiled toilet water as it is to dirty it. Simply stick one hose into the sludge, and out of another comes water so pure that it's fit for use in hospitals as well as for consumption. The process involves no chemical additives or filters, instead employing a vapor compression distiller.

While the film is named after this remarkable device, the focus of the documentary is on its indomitable inventor. Kamen is well-known for being an extremely private person, and SlingShot provides an unprecedented look into his fascinating and inspiring life. Tech Times sat down with the film's director, Paul Lazarus, to learn more about how the documentary came to be.

Lazarus followed Kamen over the course of seven years while making this film. SlingShot takes us into the most intimate corners of Kamen's life — from his home to his relationship with his family.

The inventor's more eccentric side is immediately apparent upon entering his home — which features a steam engine in the foyer, a helicopter garage with a large glass door, and, of course, a closet full of slight variations on the same all-denim outfit. To Kamen, wearing the same outfit every day is a way to save precious minutes that could be spent working. For the same reason, he has not started a family of his own.

For all of his machine-like traits, however, Kamen's humanity certainly shines through. One of the major ways the film balances out the coldness of some of Kamen's qualities is by highlighting his efforts to connect with young people through his organization, For Inspiration and Recognition of Science and Technology (FIRST). 

Perhaps most importantly, SlingShot humanizes Kamen by revealing his struggles. It drives home the point that innovation is far from easy, even for a "genius" inventor with more than 400 patents to his name — though Kamen insists: "if I'm a genius, then I'm the slowest, dumbest genius you'll ever meet."

It has taken 15 years to develop SlingShot and begin introducing it to the communities for which it was designed, though this was not for lack of effort on Kamen's part. Even he, it seems, does not have a slingshot for innovation.

SlingShot is coming to theaters in New York, Los Angeles and several other cities this July. You can find more information about screenings here.