Researchers have been inspired by the sea cucumber to build miniature robots based on liquid metal. They can change from solid to liquid state and vice versa and could be used in many fields including medicine.
Researchers have just announced that they have created metallic robots capable of solid-solid to liquid-liquid transitions. The principle is reminiscent of the T-1000 robot in the film Terminator 2: Judgment Day. However, the research team from the Sun Yat-sen and Zhejiang Universities in China and Carnegie Mellon University in the USA do not name science fiction as their inspiration, but the sea cucumber sea cucumber.
In their article published in Matter magazine, the scientists cite the properties of the sea cucumber, which makes its skin soupy or very hard in a few moments, or the octopus, which changes the rigidity of its limbs to catch objects or move. The result is a robot composed of a magnetoactive phase change material (MPTM) phase change material. The device changes phase from solid to liquid when heated by an alternating magnetic field. It can therefore change shape and then solidify at room temperature. Such a robot has a force of 21.2 megapascals and a stiffness of 1.98 gigapascals. It can move at a speed of 1.5 m/s thanks to a simple magnetic field and can carry a load of 30 kilograms.
Operation by magnetic field
The robot does not contain a motor or actuator and comes as a simple pellet or can be cast into a variety of shapes to suit your needs. It is composed of neodymeneodymium-iron-boron boron (NdFeB) alloy ferromagnetic microparticles in a low melting point liquid metal matrix. Among the various possible liquid metals, the researchers chose gallium gallium, which has a melting point of 29.8 °C, but it is possible to choose another metal that melts at a different temperature.
Researchers demonstrated how the robot worked by creating a robot in the shape of a Lego figure placed in a trap. They apply an alternating magnetic field to melt it. The liquid is then drawn through the wands. Unlike the T-1000, it cannot return to its original shape on its own and must be placed in a mold before cooling.
Replace inaccessible screws or administer medication into the stomach
Such technology would initially have applicationsMedical applications, provided that a metal is used whose melting point is higher than body temperaturebody temperature and is non-toxic… A robot is swallowed in the form of a cube. Doctors apply a magnetic field to its stomach and it encapsulates a foreign object before it solidifies, then the whole thing can be evacuated by moving the robot with a magnetic field. In the same way, the robot can contain drugs that are released in the stomach when it goes into a liquid state.
The researchers also imagined using such a robot for welding. In their example, two robots are used to push a component into place. Each robot is then liquefied thanks to a magnetic field to solder the component in place and ensure circuit operation. Your robot could also be used to swap out screws in hard-to-reach places.