Military pilots must be alert when piloting fighter jets, such as this F-15E Strike Eagle.

US Air Force photo by Senior Airman Hiram Martinez

The US military wants to develop a stimulant drug that can be turned on or off in the brain using near-infrared light. Such technology could help Air Force pilots stay alert during long combat missions while avoiding negative side effects or addiction.

gave Awareness programA project by the US Defense Advanced Research Projects Agency (DARPA) aims to develop a new version of dextroamphetamine that can be activated or deactivated by exposure to near-infrared light.