Nanomaterial for Color-Changing Robotic Skin

A new film made of gold nanoparticles can change color in response to any type of movement, like bending or twisting, and could allow robots to mimic chameleons. Robots coated in it could enter spaces that might be too dangerous or impossible for people. Developed at UC Riverside , the material can be printed and programmed to display complex patterns. When materials like gold and silver become nano-sized, their colors will change depending on their size, shape, and the direction they face. The UC Riverside team fused smaller magnetic nanorods onto larger gold ones and the two different-sized rods were encapsulated in a polymer shield, so that they would remain side by side. This enabled the orientation of both rods to be controlled by magnets. “Just like if you hold a magnet over a pile of needles, they all point in the same direction. That’s how we control the color,” said chemistry professor Yadong Yin.