Not only did it improve patients' lung function, it lowered the amount of salt in their sweat, a sign that it may combat CF at its biological root.

FORBES: Magazine Article

These can be as tiny as a millionth the size of a grain of salt which can amount to as little as a few cells of skin or sweat left in a fingerprint.

BBC: RELATED BBC SITES

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.

ENGADGET: Rocket-powered mechanical arm might boost prosthetic tech