"Electronic circuits are very sophisticated these days," said Jinxing Li, a Ph.D. candidate in Prof Wang’s lab. "But a crack, even an extremely small one, can interrupt the flow of current and eventually lead to the failure of a device. Traditional electronics can be fixed with soldering, but repairing advanced electronics on a nanoscale requires innovation."
Gadgets will soon be more ubiquitous than ever, appearing in our clothes, implants and accessories. But finding ways to fix nanocircuits, battery electrodes or other electronic components when they break remains a challenge.
Replacing whole devices or even parts can be tricky or expensive, particularly if they're integrated in clothes or located in remote places. To work toward the goal of creating devices that heal themselves, Prof Wang’s team have turned to nature for ideas.
"If you cut your finger, for example, platelets will automatically localise at the wound location and help start the healing process," Li explained. "What we wanted to do is create and use extremely small robots to perform the same function, except in an electronic system."
To accomplish this, Wang's team designed and built nanoparticles out of gold and platinum that are powered by hydrogen peroxide. The platinum stimulates the fuel to break down into water and oxygen, which propels the particles. In testing, the researchers said that the nanomotors moved over the surface of a broken electronic circuit connected to an LED. When they approached the scratch, they got lodged in it, bridging the gap between the two sides and, because the particles are made of conductive metals, they allowed current to flow again, lighting up the LED.
Li says the nanomotors would be suitable for hard-to-repair electronic components such as the conductive layer of solar cells, which are subject to harsh environmental conditions and prone to scratching. They could also be used to heal flexible sensors and batteries, which Prof Wang’s lab is also developing.
