Advertisement

If you have an ACS member number, please enter it here so we can link this account to your membership. (optional)

ACS values your privacy. By submitting your information, you are gaining access to C&EN and subscribing to our weekly newsletter. We use the information you provide to make your reading experience better, and we will never sell your data to third party members.

ENJOY UNLIMITED ACCES TO C&EN

Materials

Synthetic melanin makes color-changing skin

Humidity-driven hue shifting is fast and reversible

by Matt Davenport
August 21, 2016 | A version of this story appeared in Volume 94, Issue 33

[+]Enlarge
Credit: Chem. Mater.
An example of a synthetic melanin skin, reversibly changing from red to green with increasing humidity.
Two images in distinct colors that show the color-changing properties of a synthetic material.
Credit: Chem. Mater.
An example of a synthetic melanin skin, reversibly changing from red to green with increasing humidity.

An artificial skin made with synthetic melanin nanoparticles would make chameleons green with envy were the lizards capable of such a petty emotion. The synthetic skin changes color faster than a chameleon’s, provided the humidity of the air surrounding the engineered film changes quickly enough (Chem. Mater. 2016, DOI: 10.1021/acs.chemmater.6b02127). Although the skin can switch its hue quicker than chameleons and other color-changers in nature, it was actually inspired by them, say the skin’s developers, led by Ali Dhinojwala of the University of Akron; Nathan C. Gianneschi of the University of California, San Diego; and Matthew D. Shawkey of the University of Ghent. Iridescent bird feathers, such as those found on tree swallows, reversibly change color with changes in humidity. Scientists believe this is a result of the swelling or shrinking of feather fibers as they take on or lose moisture, respectively. The artificial skin works faster but in much the same way, with stacks of nanoparticles made from polydopamine, a synthetic melanin, playing the role of the keratin structures. Films of the nanoparticles could therefore provide the basis for rapid and easy-to-read humidity sensors, the researchers say.

Biomimetic
Watch synthetic melanin films reversibly change color with humidity in these real-time videos.
Credit: Chem. Mater.

Article:

This article has been sent to the following recipient:

0 /1 FREE ARTICLES LEFT THIS MONTH Remaining
Chemistry matters. Join us to get the news you need.