Metal robot can melt its way out of tight spaces to escape

Millimeter-sized robots made from a mixture of liquid metal and microscopic magnets can stretch, move, and melt.Can be used to repair electronic devices or remove objects from the body

To Carmela Padavich-Callaghan

Shape-shifting miniature robots can liquefy and reshape themselves, allowing them to complete tasks in hard-to-reach places or escape cages. Ultimately, it could be used as a hands-free soldering machine or as a tool for extracting swallowed toxic substances.

Robots already exist that are flexible and flexible enough to work in tight and delicate spaces like the human body, but they need to be tougher and stronger when under pressure or when they have to carry something heavier than themselves. You can not. Carmel Majidi and his colleagues at Carnegie Mellon University in Pennsylvania have created a robot that can not only change shape, but also become stronger and weaker by alternating between liquid and solid.

They created millimeter-sized robots by mixing liquid metal gallium with tiny pieces of magnetic materials made of neodymium, iron and boron. As a solid, the material was strong enough to support an object 30 times its own weight. Researchers placed it near a magnet to soften it, stretch it, move it, or dissolve it in a puddle as needed for various tasks. The magnet’s customized magnetic field applied force to the robot’s tiny magnetic bodies, causing them to move and deform the surrounding metal in different directions.

For example, the team extended the robot by applying magnetic fields that pulled these granules in multiple directions. The researchers also used a stronger electric field to pull the particles upwards, causing the robot to jump. When Majidi and his colleagues used an alternating magnetic field, electrons within the robot’s liquid metal formed an electric current. As these electric currents flowed through the robot’s body, it heated up and eventually melted.

“As far as I know, there is no other material that can change stiffness like this,” says Majidi.

Using this flexibility, the team had two robots carry small light bulbs and solder them to circuit boards. Upon reaching the target, the robot melted the end of the light bulb and fused it into the board. Electricity can then pass through the liquid metal body and light a light bulb.

In an experiment inside an artificial stomach, the researchers applied another series of magnetic fields to bring the robot closer to an object, melt it on top of it, and drag it out. Finally, they shaped the robot to look like a Lego minifigure and allowed it to liquefy and flow out between the bars to help it escape from its cage. back to

Li Zhang of the Chinese University of Hong Kong said these melted robots could be used for emergency repairs in situations where human hands or traditional robotic hands have become impractical. For example, a liquefied robot could be replaced by letting the spaceship’s lost screws flow into their place and then solidify, he says. Researchers must first develop a method to accurately track the robot’s position at every step of the procedure to ensure patient safety.