A tiny crack within an integrated chip could shut down the whole device. But what if it could fix itself so fast that the user never realises there was a problem?

A team from the University of Illinois has developed a self-healing system, based on microcapsules, that restore electrical conductivity to a cracked circuit in a split second.

As a crack spreads, the microcapsules break open and release the liquid metal contained inside. The liquid metal fills the gap in the circuit, restoring electrical flow.

"What's really cool about this paper is it's the first example of taking the microcapsule-based healing approach and applying it to a new function," said Scott White, aerospace professor, who led the study with materials science professor Nancy Sottos at Illinois.

"It simplifies the system," said Illinois chemistry professor and study co-author, Jeffrey Moore. As electronic devices are evolving to perform more sophisticated tasks, manufacturers are packing as much density onto a chip as possible.

However, such density compounds reliability problems, such as failure stemming from fluctuating temperature cycles as the device operates or fatigue. A failure at any point in the circuit can shut down the whole device, according to an Illinois statement.

"In general there's not much avenue for manual repair," Sottos said. "Sometimes you just can't get to the inside. In a multilayer integrated circuit, there's no opening it up. Normally, you just replace the whole chip. It's true for a battery too. You can't pull a battery apart and try to find the source of the failure."

Most consumer devices are meant to be replaced with some frequency, adding to electronic waste issues, but in many important applications - such as instruments or vehicles for space or military functions - electrical failures cannot be replaced or repaired.