New Materials: The Scientific Research Team Has Developed "Chameleon" Like Active Intelligent Materials

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According to the School of Chemistry and Chemical Engineering of Xiamen University, Zheng Jing, an associate professor of Hou Xu's team, and Tang Jinyao, a professor of the University of Hong Kong, have jointly developed a new type of active colloidal material that can achieve pattern and color changes by controlling light. This "chameleon" like active intelligent material is more reliable and convenient than traditional chameleon materials, It provides a simple method for color electronic paper and self powered optical camouflage. Relevant research results were published online in the international academic journal Nature.

The researchers introduced that in the application of color electronic paper, charged color particles show different convergence and distribution according to the applied voltage, so as to display different images and words. The innovation of this achievement is that this new material can be affected by light, that is, by controlling light to achieve different aggregation and dispersion patterns of particles to achieve macro color change effect, or to produce more complex micron scale structures.

The researchers designed a reactive colloid system, in which the reactive colloidal particles are encoded with spectral characteristic dyes to form a photochromic colloidal group. The particle particle interaction can be flexibly adjusted by combining different wavelengths and intensities of incident light to achieve controllable colloidal aggregation and separation.

Inspired by the photochromic phenomenon in nature, for example, cephalopods rearrange the pigment group in their skin to change their appearance by perceiving the ambient light conditions. The research team further formed dynamic photochromic ink by mixing cyan, magenta and yellow colloids, and achieved photochromism in the macro view. Different from existing color changing materials, this photochromism is based on the vertical phase stratification of light induced active colloidal mixture, that is, the rearrangement of existing components, rather than the generation of new chromophores, so it is more reliable and programmable.