This…

…is a mechanical arm developed at Vanderbilt University. An entry in DARPA’s Revolutionizing Prosthetics 2009 program, it uses space shuttle rocket technology to control movement. Says Engadget:

The arm… relies on a modified miniature version of the same rocket motors the space shuttle uses to reposition itself in space: hydrogen peroxide is burned in the presence of a catalyst to produce pure steam, which is then used to move the arm. Unlike the batteries in traditional arms, which die quickly, a small canister of hydrogen peroxide concealed in the arm can last up to 18 hours, and provides about the same power and functionality of a human arm. Cooler still is the method the arm deals with waste heat and steam: just like a regular arm, it’s allowed to filter up through a permeable skin, producing “sweat” — the same amount of perspiration you’d get on a warm summer day, according to the team.

(Via The Feed.)