The Wall Street Journal talks to Hugh Herr, founder of Cambridge-based iWalk, which makes the PowerFoot One, a robotic, prosthetic ankle and foot device. Herr is also director of the MIT Media Lab’s Biomechatronics Group.

In the video above, Herr presents his research at the World Economic Forum in Davos in January.

Last week, iWalk received $20 million of a $21 million Series B round to fund development of the prosthetic from General Catalyst and New York-based WFD Ventures.

Herr, who MHT first interviewed in 2005, was trapped in a snowstorm while climbing New Hampshire’s Mount Washington in 1982 at age 17. He was rescued, but suffered frostbite, and subsequently had both legs amputated just below the knee. The ordeal led him to take up engineering to develop better prosthetics.