Scientists at the Swiss École Polytechnique Fédérale de Lausanne have developed stretchable electronics that can be quadrupled in length, relax and re-stretch without any damage to their mechanical properties. Based on the research, the material can be stretched in any direction and lose no conductivity and exhibit no cracking, even when stretched one million times.

The conductive tracts are solid as well as flexible. They are a metallic and partially liquid film that have the potential to be used in robotics, sensors, and even artificial skin. The tracts are made with a liquid metal on a thin polymer film which gives them the support and elasticity necessary to make them stretchable. The alloy is created with gold and gallium. Gallium has high electrical properties as well as a low melting point, remaining liquid at room temperature and below, keeping it in a pliable state. The gold in the alloy keeps the gallium from separating when it touches the polymer, which would destroy its conductivity.

Electronics that can stretch up to 4 times their length. Electronics that can stretch up to 4 times their length. Typical liquid metals exhibit high surface tension, which so far has allowed only for the creation of relatively thick structures. Using this unique technique for fabrication, the team has been able to create reliable tracts that are only several hundredths of a nanometer thick.

The applications could be basic, or complex, and can change over time. The team expects the film to work for varying purposes, from artificial skin applications to creating sensors that are either incorporated into clothing or adhered to the body. It could also be used to create actuators.

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