Robot chameleon can change colour to blend into its surroundings

Guoping Wang of Wuhan University, China, and his colleagues created it to show off their camouflage technology, which could one day allow military vehicles or body armour to blend perfectly into the background.

The chameleon is a 3D-printed model covered in plasmonic displays, which produce colours by exploiting the interactions between nanoscale structures and electric fields. The team made the displays by taking a glass sheet bearing a grid of holes, each 50 nanometres across, and depositing gold on to it. This formed gold domes inside each hole. They then placed the sheet inside a casing filled with an electrolyte gel containing silver ions.

When light hits the gold nanostructures it produces ripples of electrons, called plasmons, that determine its reflective and absorbing properties – in this case, making the glass sheet appear red. Applying an electric field deposits some silver ions on to the gold domes, modifying their properties and producing different colours. Reversing the field strips off these ions and restores the red colour.

Learn more: Robot chameleon changes colour to blend into its surroundings