Mini Helicopter - Robotic Surveillance Device - Obstacle avoidance system

The helicopter in this video may weigh only 30 grams, but it carries a compass and motion sensors, can change course and warn fellow craft of obstacles it bumps into, and could even carry a small camera. It can also resist what might be called a King Kong attack – if swatted out of the air the tiny craft soon recovers and takes off again.

It was developed by researchers at Carnegie Mellon Silicon Valley in Moffett Field, California. It would make a great toy, but the team's intentions are deadly serious. They aim to fly squadrons of "Sensorfly" craft that coordinate with each other to explore indoor environments – for instance, to check out buildings after a natural disaster.

The robots are built by adding custom processors, sensors and software to rotors and motors from an off-the-shelf toy helicopter. Each prototype costs only about $200 to build, says Pei Zhang, an electrical engineer working on the project with graduate student Aveek Purohit.