March 9 (Xinhua) -- Scientists have designed a salamander robot that can switch
between swimming and walking by increasing the strength of the electrical signal
through an amphibian-like central nervous system, according to new research in
the 9 March issue of Science.
A robot that looks and moves like
a salamander and is controlled by a system that imitates
the amphibian's spinal cord, enabling the machine to alternate between swimming and
walking, is seen in this undated handout photo taken in
Switzerland. (Xinhua/Reuters Photo)
By designing a machine that can walk and swim without
redesigning its joints or central nervous system, the researchers believe the
robotic amphibian can provide answers to how the first vertebrates transitioned
from sea to land.
The 85-cm-long robot, built by Auke Jan Ijspeert and
colleagues in Switzerland and France, has a spinal cord model on board that
receives simple control signals. Sent wirelessly from a PC, the signals modulate
the speed, direction, and type of gait similarly to the signals coming from the
neural centers in vertebrate animals.
With its six spinal hinges, four rotational limb
joints, and 10motors, the robot is able to mimic the S-shaped body undulation
pattern that many amphibians use to drive themselves in terrestrial and aquatic
The researchers discovered that when the robot is
stimulated with low levels of electricity, the robot adopts a walking gait,
while higher levels cause the robot to switch to faster swimming motions.
"The salamander, an amphibian, is regarded as among the... first terrestrial vertebrates and represents a key animal from which the evolutionary changes from aquatic to terrestrial locomotion can be inferred," the authors write.
In addition to answering key questions about early evolution, the authors point out that their research is evidence of how robots can be used "as tools to test hypotheses concerning biological systems."