RIVERSIDE, Calif. Chemists at the University of California, Riverside have developed tiny, nanoscale-size rods of iron oxide particles in the lab that respond to an external magnetic field in a way that could dramatically improve how visual information is displayed in the future.
Previously, Yadong Yin's lab showed that when an external magnetic field is applied to iron oxide particles in solution, the solution changes color in response to the strength and orientation of the magnetic field. Now his lab has succeeded in applying a coating of silica (silicon dioxide) to the iron oxide particles so that when they come together in solution, like linearly connected spheres, they eventually form tiny rods or "nanorods" that permanently retain their peapod-like structure.
When an external magnetic field is applied to the solution of nanorods, they align themselves parallel to one another like a set of tiny flashlights turned in one direction, and display a brilliant color.
"We have essentially developed tunable photonic materials whose properties can be manipulated by changing their orientation with external fields," said Yin, an assistant professor of chemistry. "These nanorods with configurable internal periodicity represent the smallest possible photonic structures that can effectively diffract visible light. This work paves the way for fabricating magnetically responsive photonic structures with significantly reduced dimensions so that color manipulation with higher resolution can be realized."
Applications of the technology include high-definition pattern formation, posters, pictures, energy efficient color displays, and devices like traffic signals that routinely use a set of colors. Other applications are in bio- and chemical sensing as
|Contact: Iqbal Pittalwala|
University of California - Riverside