View post on imgur.com Two quadcopter drones just autonomously built a footbridge that is capable of withstanding the weight of a human. Outfitted with a motorized spool and plastic tubes that dispense Dyneema, a "material with a low weight-to-strength ratio," the flying machines were able to construct a lightweight tensile bridge that spans 7.4 meters between two scaffolding structures at the Flying Machine Arena in Zurich.