A simple device made of plastic and rubber can be controlled using ripples in water to move around obstacles
A small device shaped like Pac-Man can move on the surface of water and around obstacles without a motor. It could lead to the development of small robots for environmental monitoring of lakes and rivers.
Daniel Harris at Brown University in Rhode Island and his colleagues built little devices made of plastic and rubber that can be moved in a controllable way by ripples in water.
The researchers first looked at how five-pointed stars, between 0.6 and 1.1 centimetres in size, move when floating in a tank of water. Ripples produced at the surface by a separate oscillating device caused …