On one end you have military organizations designing landmines, and on the other end you've got people like Dr. P.K. Sethi and Ramachandra Sharma.
The latter two developed the Jaipur foot, a flexible and variably stiff prosthetic made of sponge-filled vulcanized rubber. Cheap to manufacture, the Jaipur foot "has helped millions of amputees in developing countries to lead normal lives," and enables users to run, climb, pedal, and even dance.
Sadly the Jaipur foot, which was developed in 1971, has recently come to our attention because Dr. Sethi recently passed away at the age of 80. But the prosthetic he and Sharma developed continues to be widely distributed.
via ny times