We have seen many interesting drones in the past. This particular drone designed at Laboratory of Intelligent Systems has 4 folding arms and a portable design. The arms unfold, so the drone can be ready for takeoff quickly. You can carry many of these small drones in your backpack.
The drone can fold/unfold its arms in about half a second. It is manufactured using an origami technique. The above video gives you a better idea how it works.