Designed with powerful winches, gecko adhesives and microspines inspired by gecko and insect feet, the FlyCroTugs (for flying, micro, tugging robots) can work together to lasso a door handle and tug the door open, removing one of many obstacles that typically poses a barrier to small flying drones.
Developed jointly by Ecole Polytechnique Fédérale de Lausanne (EPFL) and Stanford University, the FlyCroTugs came out of the laboratories run by Dario Floreano, NCCR Robotics Director, at EPFL’s School of Engineering, and Mark Cutkosky, the Fletcher Jones Chair in the School of Engineering at Stanford University.
The researchers modified micro drones so that they can anchor themselves to various surfaces using gecko adhesives and microspines, enabling the devices to land firmly and pull objects up to 40 times their weight, such as door handles or, in a rescue scenario, cameras and water bottles. Similar vehicles produced by other researchers can tug objects only about twice their weight, the researchers reported in a paper titled "Forceful manipulation with micro air vehicles" published in Science Robotics.
The paper reports that at 100 g, the FlyCroTug is able to extend its maximum force by up to 20 folds, from a maximum thrust of 2N, tugging at 40N.
The researchers note that the FlyCroTugs, because of their size, can safely navigate through tight spaces and fairly close to people, making them suitable for search and rescue missions. By holding on tightly to surfaces as they tug, the tiny robots could potentially move pieces of debris or position a camera to evaluate a dangerous situation.
By analyzing studies on how wasps capture and transport prey, the researchers were able to identify the ratio of flight-related muscle to total mass that determines whether a wasp carries its prey or drags it. Wasps also inspired them to develop various attachment options depending on where the FlyCroTugs land. For smooth surfaces, the robots have gecko grippers, a non-sticky adhesive that mimics a gecko’s intricate toe structures. They hold on by creating intermolecular forces between the adhesive and the surface.