Birds are fascinating for many reasons. Ostriches, for example, with a body weight that can easily exceed 100 kilograms, will sprint across the savanna at speeds of up to 55 kilometers per hour. These flightless birds owe their running prowess to the structure of their legs – according to a hypothesis by researchers at the Max Planck Institute for Intelligent Systems (MPI-IS). Unlike humans, birds fold back their foot while pulling up the leg towards the body when running – a feature that has remained practically unchanged since Tyrannosaurus rex in the Cretaceous period.
Quick as a bird
This principle of evolutionary success is what the researchers at the MPI-IS have now applied to a robotic running mechanism. And indeed, the BirdBot has excelled during test runs through its particularly high efficiency – just like the locomotion apparatus of live birds, explains Alexander Badri-Spröwitz, head of the research group Dynamic Locomotion at the MPI-IS. “Previously, our robots were forced to work against the spring or engage a motor while either standing or lifting a leg to ensure that the leg would not collide with the ground during the swinging phase.” This is no longer the case with BirdBot. “Altogether, it requires only a quarter of the energy compared with previous walking robots”, adds co-developer Alborz Aghamaleki Sarvestani. According to the scientists, their robot leg is amenable to scaling – even large robots can be made to run while maintaining a low energy expenditure.
Bionics is the term for this principle, which borrows strategies from animals or plants and transfers it to technology. It starts with robot grippers which simulate the arms of an octopus, to maintenance robots which swim through pipe systems by utilizing the fin movements of the ocean planarian, all the way to specialized coatings that resemble shark skin to improve the aerodynamics of airplanes. Starting this year, Lufthansa Cargo is planning to equip its entire fleet with this technology in order to save approximately 3,700 tons of jet fuel and almost 13,000 tons of CO₂ annually.
Visually, the giants of the air will bear no resemblance to the emperor of the oceans.Importantly, bionics attempts to not simply imitate its model, but instead, based on nature’s strategies, it provides innovative solutions to technological questions and demands.