Researchers at the University of California in San Diego have developed a magnetic ink which can be used to make self-healing batteries, electrochemical sensors and fabric-based wearable electrical circuits.

The key component of the ink is microparticles which are oriented in a specific configuration by a magnetic field. Due to their orientation, the particles on both sides of a break are magnetically attracted, enabling components that are printed with this ink to heal themselves. In tests carried out by the researchers, components made from this magnetic ink were able to repair breaks up to 3 mm – a new record for self-healing systems.

Existing self-healing materials require an external trigger to initiate the healing process. Then it takes several minutes to a few days until the break is healed. The new magnetic ink does not need a trigger, and the damage is repaired within roughly 50 ms.