Drones, like all aircraft, have payload capacities that are directly correlated with their size and weight. To lift something heavy, they need big props attached to powerful motors. Those use a lot power, so larger batteries are needed. That, in turn, increases the overall weight of the drone and the cycle continues. But, researchers from Stanford University are now taking a different approach that allows a small drone to move 40 times its own weight.
Their FlyCroTug drone design was heavily inspired by nature, and wasps in particular. When a wasp kills prey that is too large to carry while flying, it will drag the food across the ground. The FlyCroTug drones work in the same way by landing and using a winch to pull objects towards themselves. That technique gives them the ability to move objects that weigh far more than they do.
In order to stay anchored to the ground, the FlyCroTug drones have special feet that have either “gecko grippers” or barbs. The metal fishhook-like barbs can be used to securely grasp rough surfaces like carpet. For smooth, flat surfaces they use the gecko grippers, which are non-sticky adhesives that can hold on to the surface with intermolecular forces. As the team demonstrates in the video above, just two FlyCroTug drones can be used to open a heavy door. The researchers imagine this capability being useful in search and rescue operations, because the small drones can fit into tight spaces and move relatively large objects.