Chameleon Metals
A New Discovery:
Chameleon metals change their surface structure in response to heat
Engineers at Iowa State University have developed a novel technology that allows metal surfaces to change their structure in response to heat, akin to how chameleons change color based on their environment. By carefully selecting stimuli and reaction conditions, the surface of a liquid metal alloy can be tuned, resulting in the alteration of surface patterns and compositions with temperature or other stimuli. This breakthrough could lead to the development of smart alloy systems with applications ranging from sensing to catalysis. The process involves controlling the rate of composition inversion by heat to modify the metal's surface characteristics. By inducing different levels of heat, specific elements like gallium, indium, and tin are brought to the surface in a controlled manner, allowing for the precise programming of surface textures for various applications. This innovative technology could have implications for enhancing metal performance, protecting metals from damage, and modifying their tribological and optical properties.
Read more:
https://www.news.iastate.edu/news/2020/01/10/chameleonmetals
This illustration shows how a particle of "chameleon metal" reacts to higher and higher temperatures by sequentially changing its surface structure. Image by Andrew Martin.
Read the paper:
"Chameleon Metals: Autonomous Nano‐Texturing and Composition Inversion on Liquid Metals Surfaces," Angewandte Chemie; Volume 59, Issue 1; January 2, 2020; DOI: 10.1002/anie.201912639