Engineers from the University of California, San Diego have brought together a couple of nascent technologies that could result in inexpensive and long-lasting electronic devices. The team created a magnetic ink that can print a variety of self-healing components.
The ink is loaded with inexpensive microparticles made of neodymium that are magnetically oriented in such a way that if the material rips, each side of the tear is attracted to the other. This allows components printed with the ink to self-repair tears as wide as 3 mm, which the researchers claim is a new record.
We've seen similar properties in boron nitride nanosheets that can repair themselves even after being cut in half, but that material doesn't conduct electricity. Batteries have been developed that can be self-repaired when they rupture in a similar fashion and other components have been implanted with capsules that rupture when cracks develop in the circuits, releasing a liquid that fills in the crack and dries instantly to restore conductivity.
But this magnetic ink comes with the obvious bonus of being printable, like many other conductive inks out there, and able to repair itself almost instantly for most practical purposes.
"We wanted to develop a smart system with impressive self-healing abilities with easy-to-find, inexpensive materials," said Amay Bandodkar, one of the first authors of the paper detailing the research.
The researchers damaged devices created with the ink in four different places and also damaged the same spot over and over again a total of nine times. Each time they say it healed with a minimal loss of conductivity.
One test involved a circuit on the sleeve of a shirt that connected a small battery to an LED light. The circuit and fabric it was printed on were cut and the light went off but came back on within a few seconds after the material pulled itself together and restored conductivity.
The researchers say the ink could be used in a variety of applications to create components including self-healing batteries, electrochemical sensors and wearable electronics. Future inks could also be engineered with different ingredients for an even wider range of applications.
The paper on the research is published in the journal Science Advances and the ink's self-healing capabilities are demonstrated in the video below.
Source: UC San Diego