Search Menu
Photonics Media Photonics Buyers' Guide Photonics EDU Photonics Spectra BioPhotonics EuroPhotonics Industrial Photonics Photonics Showcase Photonics ProdSpec Photonics Handbook
More News
Email Facebook Twitter Google+ LinkedIn Comments

Self-Assembled Films Display Structural Color

Photonics Spectra
Oct 2005
Daniel S. Burgess

Scientists at Keio University in Yokohama, Japan, have developed a colloidal “ink” that becomes iridescent upon drying as a result of diffraction. Such materials that produce colors structurally have a variety of potential applications, including as colorimetric chemical and physical sensors and as alternatives to the variable pigments used as anticounterfeiting measures on documents and banknotes.

Self-Assembled Films Display Structural Color
The colloidal “ink” becomes iridescent upon drying as a result of diffraction. It works equally well on glass, plastic and gold. Courtesy of Haruma Kawaguchi, Keio University.

The new ink is an aqueous dispersion of poly(N-isopropylacrylamide) microspheres produced by precipitation polymerization, with the size of the particles determined by the reaction parameters. As the swollen particles dry on a surface to which they have been applied, capillary forces cause them to settle into a regular pattern. When all of the water has evaporated, the flattened spheres remaining form a periodic structure that diffracts light.

In tests with spheres that had hydrodynamic diameters of 964 and 848 nm, the researchers found that the suspension of larger particles produced more brilliantly iridescent films. They also found that the ink formed the films when it was sprayed or written onto a surface, and that the films formed equally well on glass, plastic and gold.

colorimetric chemicalKeio Universityphysical sensorsResearch & TechnologySensors & DetectorsTech Pulse

Terms & Conditions Privacy Policy About Us Contact Us
back to top
Facebook Twitter Instagram LinkedIn YouTube RSS
©2018 Photonics Media, 100 West St., Pittsfield, MA, 01201 USA,

Photonics Media, Laurin Publishing
x Subscribe to Photonics Spectra magazine - FREE!
We use cookies to improve user experience and analyze our website traffic as stated in our Privacy Policy. By using this website, you agree to the use of cookies unless you have disabled them.