Jumping robot breaks the altitude record

"Nature as a role model: a robot sets a new record with a jump height of over 30 meters. This is possible thanks to a sophisticated mechanism.

The leaping robot developed by researchers from the University of California and Caltech in Pasadena is reminiscent of a machine from Leonardo da Vinci's workshop.

The strangely shaped creature weighs only 30 grams and jumps over 30 meters high.

That is almost three hundred times its own size.

Elliot Hawkes and his colleagues write in Nature magazine that neither the best hopping robots nor the record-holders among jumping creatures can compete with this. The 70-centimetre-long foam cicada – it was the inspiration for the researchers – manages to jump 115 times its body length.

Engineers have been developing jumping machines for decades. They often get inspiration from nature. For most creatures, the maximum jumping height is determined by the jumping power of their leg muscles. Insects also use the advantage of their long hind legs to be able to hop as far as possible. Jumping robots are usually equipped with actuators such as ratchets, torsion springs and motors.

In order for a robot to be able to jump as high as possible, as much energy as possible must be stored in the actuators before the jump. One indication of this is the starting speed. The record holder from the laboratory of Hawkes and his colleagues accelerates from 0 to 28 meters per second within nine milliseconds. In the process, energy of 24.2 joules is suddenly released, as simulations have shown. For the researchers, the realization that, unlike living beings, the weight of jumping robots is less important than the jumping mechanism was enlightening when it came to design. The apparatus from California is ten times heavier than its natural counterpart.

The researchers use a rotary motor and a sophisticated spring effect as the drive: Four elastic carbon fiber plates are bent extremely strongly using rubber bands and a traction cable, which is connected to a rotary motor, and in the process are placed under great tension. If this is large enough, a pawl at the upper end of the pull rope is released, whereupon the rubber bands suddenly relax. The robot takes off. The carbon fiber plates and housing with the rotating motor take on an aerodynamic elongated shape during flight. After landing, the rotating motor tightens the traction cable again and the whole process starts again. It takes two minutes to restart.

The key advantage of jumping robots is that they can overcome obstacles with ease. This makes jumping robots interesting for exploring inaccessible areas, such as mountains of rubble after an earthquake or in rugged terrain on alien planets. However, it must be possible to vary the height and direction of the jump, which is not the case with the apparatus used by Hawkes' researchers. Now you want to optimize the jumping robot so that it jumps even higher."