DARPA has spent almost $25 million funding two independent teams, Mr. Kamen’s DEKA Research & Development Corp. and a group at Johns Hopkins’ University in an effort they hope will ultimately lead to commercial prosthesis that can be controlled from the human brain.

The innovation in the DEKA arm lies in its ultra light weight carbon shell, giving the user an exoskeleton with which to gain the leverage necessary to do some of the extraordinary things the system makes possible, such as lifting a 40 lb. weight.

To make the system function, the DEKA engineers coated the inside of the shell with a mosaic of thin air bladders that can be individually filled with air to offer padding and rigidity necessary to make possible normally ordinary tasks such as operating a portable power drill. When the arm is not in use the system deflates, or can even alternately fill and empty to offer a massage effect, so that it is not painful to wear for long periods.

The DEKA system is controlled by a joystick that is moved by the remaining portion of the user’s arm and by a second control mechanism in the user’s shoe. Mr. Kamen said that despite the complexity of controlling an ensemble of motors and mechanical servo devices, a user can gain basic functional control in just one day.