Flexible substrates and semiconductors could lead to electronic devices such as wearable medical diagnostic devices and roll-up displays. However, the thin wires linking different circuit components in existing flexible electronics are prone to breakage when bent, making them unreliable. The scientists Amit Kumar and Sanjay Sambandan of the Indian Institute of Science, Bengaluru, in collaboration with scientists from the University of Cambridge, have found a way for damaged electronic circuits to repair themselves. In a paper published in a recent issue of “Physical Review Applied”, the researchers reported that a suspension of copper particles could fix breaks in electronic connections.
Unlike previous such techniques, this method does not require rare materials or the addition of complex circuitry. The idea is based on submerging a circuit connection in a solution containing suspended copper microspheres. If the connection gets broken, an electric field will cause the copper spheres to form chains that bridge the gap. The current flowing through the chains will then heat and sinter them, creating a stable wire that heals the connection. In contrast to the reconnections produced by other self-healing experiments, the copper-sphere patch is both flexible and stretchable.