Fudan University researches and develops new intelligent display structural color film materials

Wu Limin, a professor of the Department of Materials Science at Fudan University, assembled a polymer colloidal microsphere with a diameter of a few microns to a dozen microns on the adhesive layer of a common transparent polymer tape into a single-layer microsphere array. The reflection also has a color-dependent and color-invariant thin film material with intelligent response structural color, and reveals the formation mechanism of the intelligent response structural color. Related results were published online in "Science Progress" recently. It is reported that the study has applied for one patent each in China and the United States.

Compared with traditional chemical colors (such as pigments, dyes, etc.), structural colors have the characteristics of high color reflectivity, high saturation, not easy to fade, and environmental protection, but the existing natural or synthetic structural color materials are not intelligent Response characteristics.

The large-area retro-reflective structured color film developed by the Wu Limin team showed colorlessness in both indoor and outdoor surfaces. However, under a white light source, the non-spherical film surface displayed a retroreflective smart structure colour. "The reason for this novel optical phenomenon is that a unique double-layer structure based on air cushion microspheres / polymers is formed between the polymer colloidal microspheres and the transparent tape." Wu Limin told the "China Science News" when the white light beam When the film enters from the non-microsphere side of the film, light interference will occur at the hemispheric interface of the part of the microsphere and the part of the microsphere, respectively, and the effect of film interference and total internal reflection will occur respectively, thereby sequentially achieving the effect of intelligent structural color generation and retroreflection. By adjusting the particle size of the microspheres, the thickness of the air layer can be controlled to produce structural colors of different colors.

The researchers said that the retro-reflective structure color film has important application value in the fields of intelligent display and traffic safety reflective facilities. (Reporter Huang Xin)