Inspired by snake-monster lizards, scientists have created amphibious robots that can “run” on the water

The snake monster lizard is also known as the Jesus Christ lizard because it can run on the water. A new version of an existing robot can do the same thing, and it can cross rugged terrain. Developed by a team at Ben Gurrian University in Israel, AmphiSTAR, inspired by snake monster lizards, is the newest member of the university’s STAR robotics family.

The original Flying Sprawl-Tuned Autonomous Robot robot featured an adjustable angled arm with wheels on one side and propellers on the other. This setting allows it to roll along the ground like a car or fly like a four-winged aircraft.

Subsequent RSTAR robots retained round wheels on one side but replaced the propellers with non-spoke wheels on the other. It uses round wheels to move on flat terrain, but actually flips itself over and uses spoke wheels to travel on rough, uneven ground.

The “palm-sized” AmphiSTAR retains a leg-type expandable arm and is now equipped with a total of four propellers — two at the bottom of each arm. As it moves on surfaces such as grass or gravel, the angle of the arm makes the propeller blades function like RSTAR’s endless spokes, digging and pulling the robot forward. This configuration allows it to crawl at a top speed of 3.6 meters per second.

When it reaches the water body, it continues to use the propeller, which now allows it to “run on the water” at speeds of up to 1.5 m/s. In other words, it can also move more slowly and more like a boat over the water, maintaining its buoyant power with a pair of buoyant tanks. Future plans include ability to swim underwater.

“We envision AmphiSTAR for agricultural, search-and-rescue, and excavation applications where both crawling and swimming are needed,” said Dr. David Zarrouk, director of the university’s Bio-Inspired and Medical Robotics Laboratory.

The robot was demonstrated last week at an international conference on online intelligent robots and systems.