Researchers at the Paul Scherrer Institute PSI and ETH Zurich have developed a micromachine that can perform different actions.
First nanomagnets in the components of the microrobots are magnetically programmed and then the various movements are controlled by magnetic fields. Such machines, which are only a few tens of micrometres across, could be used, for example, in the human body to perform small operations.
The robot, which measures only a few micrometres across, is reminiscent of a paper bird made with origami – the Japanese art of paper folding. But, unlike a paper structure, the robot moves as if by magic without a visible force. It flaps its wings or bends its neck and retracts its head. These actions are all made possible by magnetism.
Researchers at the Paul Scherrer Institute PSI and ETH Zurich have assembled the micromachine from materials that contain small nanomagnets. These nanomagnets can be programmed to assume a particular magnetic orientation. When the programmed nanomagnets are then exposed to a magnetic field, specific forces act on them. If these magnets are located in flexible components, the forces acting on them cause the components to move.
The nanomagnets can be programmed again and again. This reprogramming results in different forces, and new movements result. For the construction of the microrobot, the researchers fabricated arrays of cobalt magnets on thin sheets of silicon nitride. The bird constructed from this material could then perform various movements, such as flapping, hovering, turning or side-slipping. The researchers have now published their results in the scientific journal Nature.
Source: “Flying by magnetism”, Zurich ETH News