Researchers from the École polytechnique fédérale de Lausanne (EPFL) have developed stretchable conductive tracks that can bend and stretch four times their original length. These stretchable electronics can potentially be used in artificial skin, clothing and sensors that require body contact.
“We can come up with all sorts of uses, in forms that are complex, moving or that change over time,” said Hadrien Michaud, a PhD student at the Laboratory for Soft Bioelectronic Interfaces (LSBI) and a study author, in an article published by the EPFL.
The stretchable electronics are solid and flexible, with a metallic and partially liquid film. This malleable consistency makes it ideal for application in artificial skin or prosthetics. The fluid nature of the stretchable conductive tracks makes it plausible that the material can be used in fabric to potentially monitor biological functions, writes the EPFL.
But the buck doesn’t stop there. The stretchable electronics are also tough. “Using the deposition and structuring methods that we developed, it’s possible to make tracks that are very narrow – several hundredths of a nanometer thick – and very reliable,” said laboratory manager Stéphanie Lacour, holder of the Bertarelli Foundation Chair in Neuroprosthetic Technology.
The unique nature of the conductive tracks can be attributed to both the researchers’ unique fabrication technique, and the materials used to create the tracks: an alloy of gold and gallium. “Not only does gallium possess good electrical properties, but it also has a low melting point, around 30o,” said Arthur Hirsch, a PhD student at LSBI and co-author of the study. “So it melts in your hand, and, thanks to the process known as supercooling, it remains liquid at room temperature, even lower.” The layer of gold ensures the gallium remains homogeneous, preventing it from separating into droplets when it comes into contact with the polymer, which would ruin its conductivity.
Watch the video above for more about the stretchable electronics.