“Scientists have been developing magnetically controlled soft robots for years. Most existing materials for these bots are made of either stretchy but solid materials, which can’t pass through the narrowest of spaces, or magnetic liquids, which are fluid but unable to carry heavy objects (SN: 7/18/19).
In the new study, researchers blended both approaches after finding inspiration from nature (SN: 3/3/21). Sea cucumbers, for instance, ‘can very rapidly and reversibly change their stiffness,’ says mechanical engineer Carmel Majidi of Carnegie Mellon University in Pittsburgh. ‘The challenge for us as engineers is to mimic that in the soft materials systems.’
So the team turned to gallium, a metal that melts at about 30° Celsius — slightly above room temperature. Rather than connecting a heater to a chunk of the metal to change its state, the researchers expose it to a rapidly changing magnetic field to liquefy it. The alternating magnetic field generates electricity within the gallium, causing it to heat up and melt. The material resolidifies when left to cool to room temperature.”
Learn more on “These shape-shifting devices melt and re-form thanks to magnetic fields” via ScienceNews.