Researchers at the École Polytechnique Fédérale de Lausanne (EPFL) in Switzerland have developed a robot which accurately mimics the gait and movement of a salamander. ‘Pleurobot’ consists of 3D printed bones and motorized joints, and could be used in the development of medical devices.
While X-rays are most commonly used to look at broken bones and other human bodily problems, the technology can also be used to learn about animals, potentially paving the way for radical new developments in robotics, medicine, and other fields. When a team of scientists from EPFL’s Biorobotics Laboratory recently put a live salamander under an X-ray, they weren’t sizing it up for a new leg brace. Instead, they wanted to observe the motion of the ancient amphibian’s skeleton in order to better understand how it moves, enabling them to build a realistic robotic version of the creature and learn a thing or two about the evolution of vertebrate locomotion at the same time.
The partially 3D printed salamander robot consists of 3D printed bones, motorized joints, and a “nervous system” made up of electronic circuitry. A fun project then, but the researchers also believe the robot to be more biomimetically realistic than any other robo-salamanders out there. And no, before you ask, that’s not an insignificant achievement: the EPFL team, led by Prof. Auke Ijspeert, had actually developed a number of realistic salamander robots before Pleurobot, but none of those previous models were designed with close reference to the 3D motion of the creature’s skeleton.
Pleurobot, then, is a salamander robot like no other. By capturing X-ray videos of a real, living Pleurodeles waltl from the top and side, tracking 64 individual points on its skeleton, the scientists were able to observe the amphibian’s skeletal motions while it made different kinds of movement on the ground and in water. By mimicking those skeletal movements, the 3D printed robot is able to walk and swim in much the same way as its living counterpart. “What is new is really our approach to building Pleurobot,” Ijspeert explained. “It involves striking a balance between designing a simplified bone structure and replicating the salamander’s gait in three dimensions.”
Although directly inspired by the skeletal movement of the salamander, Pleurobot actually contains fewer “bones” than the real creature, with 27 motors and 11 segments making up entire spinal section. The salamander, on the other hand, has 40 vertebrae and multiple joints able to move different directions. Despite being anatomically simpler than its organic inspiration, however, the 3D printed robot actually contains the minimum number of segments required to accurate replicate the motion of the salamander.
It has been demonstrated that electrical stimulation of the salamander’s spinal cord determines whether it walks, crawls, or swims, but by observing and robotically replicating the movements of the creature, Ijspeert and co can now learn more about how exactly the spinal cord controls bodily movement—not just in the salamander, but in humans too. With this knowledge, the EPFL scientists and their peers may be able to develop future therapies and neuroprosthetic devices for amputees and paraplegic patients.
“Animal locomotion is an inherently complex process,” said Kostas Karakasilliotis, designer of the early versions of the Pleurobot. “Modern tools like cineradiography, 3D printing, and fast computing help us draw closer and closer to understanding and replicating it.”
Originally Posted in 3ders> Printing Application.