What's more, a quadriplegic woman with sensors implanted onto her brain controlled one of the robotic limbs to grab a cup, shake hands and eat a chocolate bar. She even flew an F-35 Joint Strike Fighter simulator using just her thoughts.

Now, the Defense Advanced Research Projects Agency (DARPA) wants to expand on that cutting-edge work to build other potential breakthrough medical technologies, including a pacemaker-sized device that might someday improve the memory of troops who suffered a traumatic brain injury. Think of it as a hard drive of sorts for the brain.