Among Dean Kamen’s many innovations is the Slingshot, a water purification device that can produce 1000 liters of clean water per day at relatively small hourly power costs. (Coca-Cola has been helping to get the devices placed in rural areas.) Kamen has been working on the device for over 15 years, and the major struggle remaining is not with the device, but with getting it to where it’s needed.
A documentary tracing the development of the Slingshot has been traveling the festival circuit since March. It starts with the initial idea, and runs up through recent trials of the device in Ghana. You can watch a short clip online.