Soft robots are gaining a lot of attention in research circles, largely due to the safety benefits for humans who might need to work in their vicinity, and from an engineering lab at the University of California, San Diego comes an interesting new example of this technology in the form of a robot that is powered by pressurized air and can move without any electronics.
Inflatable components and air pressure have played a key part in soft robotics research, from machines that can run like a cheetah, to inflatable grippers that handle delicate objects with care. But most of these solutions require electronic circuits, pumps and power sources to function, driving up the cost and complexity of the final product.
The UC San Diego team has designed a soft robot that is instead controlled through what are described as pneumatic circuits. These consists of a system of cylindrical chambers making up the four legs, which work with oscillating valves that allow pressurized air in and out in certain sequences.
This causes bending of the legs, which each have three degrees of movement, and when carried out in the correct sequence, enables the robot to move across the floor. The team designed the pneumatic control circuits to generate a walking gait inspired by sideneck turtles, and also built in sensors in the form of tiny bubbles at the end of a boom extending from the robot's body. This means that when the robot encounters an obstacle, the bubble becomes depressed, flips a valve and sends the robot moving back in the opposite direction.
"This work represents a fundamental yet significant step towards fully-autonomous, electronics-free walking robots," says Dylan Drotman, first author of the paper describing the technology.
In addition to children's toys, the researchers say the technology also could also find applications in places where electronics can't operate, such as in mine shafts and MRI machines. The team also hopes to build on this research by developing versions of the robot that can navigate rougher terrain and more complex obstacles. Their future plans also include investigating how these pneumatic circuits could be used to handle simpler functions like walking in hybrid robots, while conventional electrical circuits provide the power and actuation to handle more complicated tasks.
The research was published in the journal Science Robotics, while the video below shows the robot in action.