Late last year, we wrote about a foldable drone from Davide Scaramuzza’s lab at the University of Zurich that could change its shape in mid-air to squeeze through narrow gaps. That drone used servos to achieve a variety of different configurations, which made it very flexible but also imposed a penalty in complexity and weight. At ICRA in Montreal earlier this year, researchers from UC Berkeley demonstrated a new design for a foldable drone, able to shrink itself by 50 percent in less than half a second thanks to spring-loaded arms controlled by the power of the drone’s own propellers.