Low-temperature manufacturable, recyclable, and reconfigurable liquid-metal bonded NdFeB magnets for sensors and robotics

This work presents a recyclable liquid-metal/NdFeB composite magnet (LM magnet) with a reconfigurable shape and polarity. Taking advantage of the low-temperature phase-transition property of LMs, we can re-orient the NdFeB particles and reshape the LM magnets, to produce complex magnetization profiles or complex structured magnets. The manufacturing of LM magnets was realized at low temperatures by using a template and paired permanent magnets. The microscopic morphology and elemental composition of the LM magnet were analyzed by scanning electron microscopy and energy dispersive spectroscopy, respectively. The magnetic properties and phase-transition properties of the LM magnet were analyzed using a vibrating sample magnetometer (VSM) and a differential scanning calorimeter. The experimental results verified that the LM magnet can be recycled, reconfigured, and welded. The configurable magnetization profile with a resolution of up to 800 µm demonstrates that manufacturing of complex magnetic poles can be achieved through this technique. Finally, three application cases show the application prospects of the LM magnet in robots and sensors.