He whizzes over 30 meters high in the air: Researchers have developed a robot that can jump to 100 times its own size. It surpasses previous artificial jumpers and also the performance of biological systems. The concept is based on the sudden release of a tensioned system of springs and rubber bands. In the case of jumping, this technique is superior to biology due to more efficient storage options for elastic energy, the scientists explain. According to them, jumping robots could provide a bird’s-eye view of terrain in an economical way. This could be particularly effective when exploring the lunar surface.
As is well known, there is an alternative way to fly, at least for a short time: people also occasionally use jumps to overcome obstacles or to reach something high up. However, our abilities are quite modest: the world record is 2.45 meters at a height of 1.93 meters. In relation to their body size, however, some animals achieve much higher performance. However, the particularly strong jumping power of insect species such as grasshoppers and the like is based on a concept that differs significantly from our process.
While humans and other larger creatures use spontaneous muscle contractions to jump, the record jumpers of the insect world first build up stored elastic energy through muscle tension. Through certain mechanisms, the potential can then be suddenly released, which means that the animals are transported up very efficiently. This basic principle from biology has already been used to make robots jump. As the researchers led by Elliot Hawkes from the University of California in Santa Barbara report, they have now been able to take this process to the extreme.
Cleverly promoted to the top
Her jumping robot, which is 30 centimeters high, has an aerodynamically shaped head that houses a battery and a motor. During the tension phase, it creates a rotary movement, which causes a cord to be wound onto a pivot. Its lower end is attached to four arcuate elements made of an elastic carbon fiber material. As the line is wound, they deform under the pulling force and thereby store elastic energy. This effect is additionally reinforced by rubber bands that are stretched between the arch elements like spokes. Full charge is achieved when a wedge attached to the cord makes contact with a latch in the robot’s head and snaps into place. This element is then opened to trigger the jump. The tension of the rope breaks down immediately and the elastic energy stored in the arch elements and rubber bands is suddenly released.
As the researchers report, the results of their investigations during the tests revealed: The robot, which is 30 centimeters high and weighs 30 grams, zooms to a height of up to around 33 meters. When taking off, it reaches a speed of more than 28 meters per second. According to the scientists, this is the highest performance ever achieved in technical jumpers and will also outperform biological systems. Although some insects achieve a similar ratio of body length and jumping height, this is limited to lightweights and their take-off speed is only about four meters per second. At 30 grams, Hawkes and his colleagues’ robot is more than ten times heavier than the largest jumping creatures with concepts of stored elastic energy.
alternative to flying
As the researchers explain, the more effective ways of storing elastic energy allow the technique to take advantage of biological methods. Because the maximum jumping performance of animals is limited by the effect their muscles can produce in a single stroke. The potential of a technical jumper, on the other hand, can reach a higher level, since a rotary motor can provide significantly more stored energy via the winding effect. “Our work advances the understanding of mechanisms involved in jumping, points to possible efficiencies, and underscores the importance of considering the differences between artificial and biological systems,” write Hawkes and his colleagues.
As they conclude, the power of their design also demonstrates the potential for using jumping robots. They could therefore represent a practical alternative to flying objects, because they are able to overcome obstacles and reach heights that were previously reserved for drones and the like. This allows them to gather visual data of the terrain from a bird’s eye view when jumping. This would be particularly interesting when exploring the moon, for example: due to the lower gravity, the current model could jump 125 meters and cover half a kilometer in a single leap, the scientists write.