Pasta-shaped robot with no moving parts can navigate through mazes

Matthew Sparkes is a writer.

A soft robot with no motors, batteries or computers can roll over a range of surfaces and escape simple mazes by harvesting heat energy and turning it into motion.

Jie Yin and his colleagues at North Carolina State University created a spiral-shaped device from a narrow piece of rubber-like material. The areas of the robot touching the surface warm up and expand when placed on a surface that is at least 55 degrees C. The device is rolled along at speeds up to 3.8 millimetres per second.

The robot is able to do relatively complex tasks, such as navigating mazes. The orientation of the soft robot is slightly changed when it reaches an obstacle. It will push against the obstacle until the tension in the device changes, which will cause it to change shape from one orientation to another. It rolls away in the opposite direction.

When placed in a maze it will continually change direction when meeting obstacles, bumping from surface to surface, eventually finding its way out despite lacking any intelligent control.

The soft robot was able to roll over smooth surfaces in tests. At an angle of 15 degrees to the horizontal, it could cope with sand dunes. The 12-centimetre-long robot was able to push a cylinder along.

Read more: Robot can fly, swim or hitch a ride by sticking to other objects

Yin says that the soft robot's capabilities are limited by the different ways that newly discovered materials can respond to stimuli.

He says that it will not work without both of them. You can already achieve such interesting things with a simple twist. If you make this guy more complex, like a more complex 3D structure, I believe it will encourage more advanced capabilities.

Yin believes that the technology could be used to create cheap robots that can explore environments and take sensor readings, and that they could even be made on a tiny scale for use in the human body.

There is a journal reference in the PNAS.