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Electronic Materials

Chemistry In Pictures

Chemistry in Pictures: Electronic pigment

by Manny I. Fox Morone
August 9, 2022


A series of panels showing a maple-leaf-shaped device as it changes color from red to green to blue with increasing voltage.
Credit: Yiquan Fang/CCWang Lab

Yiquan Fang watched this leaf change color before his eyes—or at least he saw the liquid crystals inside this leaf design change color. Fang, a graduate student in Changchuan Wang’s lab at Fudan University, works with electrochromic liquid crystals, repeating structures that change their molecular organization when exposed to different voltages. These crystals are composed of self-organizing nanospheres of silica. As the voltage across the device increases, the nanospheres are drawn closer together and create a “tighter” structure. This tight structure amplifies shorter wavelengths of light, which our eyes interpret as bluer colors. Meanwhile, “looser” structures amplify redder colors. The goal is to one day use color-changing technology like this in full-color displays.

Credit: Yiquan Fang/CCWang Lab. Read the full paper in ACS Applied Nano Materials.

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This story was updated on Aug. 31, 2022, to correct one of the researchers' names. The head of the lab at Fudan University is Changchun Wang, not Chongchuan Wang


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