Researchers at the Swiss Federal Institutes of Technology in Lausanne (EPFL) have developed Gimball, a spherical flying robot that is protected by an elastic cage that enables it to absorb and rebound from impacts. The robot keeps its balance using a gyroscopic stabilization system. "The idea was for the robot's body to stay balanced after a collision, so that it can keep to its trajectory," says EPFL's Adrien Briod. The researchers developed the gyroscopic stabilization system consisting of a double carbon-fiber ring that keeps the robot oriented vertically, while the cage absorbs shocks as it rotates. Most robots navigate using a complex network of sensors, which enable them to avoid obstacles by reconstructing the environment around them. However, the EPFL researchers say this is an inconvenient method. "The sensors are heavy and fragile," Briod notes. "And they can't operate in certain conditions, for example if the environment is full of smoke." Gimball is designed to handle the most difficult terrain. "Our objective was exactly that--to be able to operate where other robots can't go, such as a building that has collapsed in an earthquake," Briod says. "The on-board camera can provide valuable information to emergency personnel."