A swarm of buzzing dragonfly bots passes overhead. Suddenly, they make a kamakaze dive toward a nearby tree--but wait a minute, instead of crashing and careening to the ground, they're sticking to the tree. Resting, recharging, waiting for orders. All thanks to Mirko Kovac's new system allowing swarming robots to perch on nearly any surface, then take off again.

Working out of Switzerland's École Polytechnique Fédérale in Lausanne, Kovac's mechanism uses two needles mounted to the front of a small glider or robo-copter. When extended, the 'bot can fly straight into the surface it intends for its perch--no additional landing maneuver's necessary. When it's time to take off again, an electric motor and gearbox connected to the needles pulls them out, and flight resumes. Kovac claims the needles work on a variety of different surfaces, including concrete and wood. The whole assembly weighs just 4.6 grams.