The Pancake-Like Legless Soft Jumping Robot Leaps More Than Seven Times Its Own Height

A team of roboticists have come up with a novel design for a jumping robot: a soft pancake, which despite its lack of legs can leap more than seven times its own height on-demand.

"Jumping is an important locomotion function to extend navigation range, overcome obstacles, and adapt to unstructured environments," the team explains of its work. "In that sense, continuous jumping and direction adjustability can be essential properties for terrestrial robots with multi-modal locomotion. However, only few soft jumping robots can achieve rapid continuous jumping and controlled turning locomotion for obstacle crossing."

The team's contribution to the field: A soft robot shaped like a pancake, entirely devoid of legs. Driven electrohydrostatically, the robot is capable of both forward momentum and leaping — and does both with impressive results, leaping more than seven times its own height and propelling itself forward at a rate of just over six body lengths per second.

The Legless Soft Jumping Robot, or LSJR, was inspired by hydraulically amplified self-healing electrostatic (HASEL) actuators, but modifies the design to improve its leaping abilities.

"We show that LSJR’s rapid continuous jumping locomotion can cross various obstacles, including slopes, wires, single steps, continuous steps, ring obstacles, gravel mounds, and cubes of different shapes, some of which are larger than the robot," the team notes. "The turning speed of the dual-body LSJR was able to reach 138.4°/s⁻¹, which is the fastest among existing soft jumping robots."

Speaking to the New York Times, which brought the work to our attention, an unaffiliated research scientist, Wenqi Hu, PhD, suggested that the robot could be given the job of exploring alien worlds. "This type of task requires a simple but robust miniature robot design," he told the paper, but warned that the materials used would need to be suitable for extraterrestrial use.

The research team itself, meanwhile, found the LSJR suitable for detecting and recording environmental conditions using a a lightweight sensor and photochromic dyes, and that additional sensors could allow it to track down pollutants in factories and buildings — once they've freed the LSJR of its current tether.

The team's work has been published under open-access terms in the journal Nature.