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.



Iridescent fish inspires a new color-changing device

The prototype device mimics the neon tetra’s venetian-blind mechanism of changing colors

by Neil Savage, special to C&EN
April 12, 2019 | A version of this story appeared in Volume 97, Issue 15


Photo of a neon tetra fish with aquarium plants in the background.
Credit: Lapis2380/Shutterstock
A new color-changing device was inspired by the neon tetra’s iridescent scales.

A common aquarium fish, the neon tetra, has given researchers inspiration for a new type of color-shifting device (ACS Nano 2019, DOI: 10.1021/acsnano.9b00822). The colorful fish (Paracheirodon innesi) produces iridescence through light bouncing off stacks of guanine platelets in its scales. By tilting the platelets, the fish can change the spacing between them and the wavelength of light they reflect. Chih-Hao Chang of North Carolina State University and colleagues built a device that mimics this mechanism. First they molded a siloxane copolymer containing iron oxide nanoparticles into a block studded with 1 µm tall pillars spaced 2 µm apart. They then surrounded the pillars with more nanoparticles dispersed in water and topped the device with a layer of poly(dimethylsiloxane). When they applied a magnetic field, the nanoparticles in the water arranged themselves into 20 µm high columns on top of the polymer pillars. Changing the angle of the magnetic field tilted the columns backward or forward up to 30°, quickly switching the color from yellow to green and back again. The technology might one day provide soldiers with camouflage or form the basis of a new type of display screen, the researchers say.


This article has been sent to the following recipient:

Chemistry matters. Join us to get the news you need.