Proteinic Artificial Skin with Molecularly Encoded Coloration

An ability to integrate adaptive coloration and tissue-like compositions, structures, as well as mechanical properties, and so forth into a material remains elusive. To address this problem, this work presents a solution whereby these features were integrated into a proteinic artificial skin through biomimetic design. In this artificial skin, silk fibroin was used to mimic the structural framework of the cytoskeleton due to its unique molecular network structure and outstanding and tunable mechanical properties. Meanwhile, a thermochromic filamentous network consisting of C25-GAGAGAGY amphiphilic peptides was designed to mimic the functional tracks in the cytoskeleton, enabling its temperature-adaptive coloration ability. The interconnected linkage between the structural frame and functional units makes this artificial skin have stable structures, mechanical properties, and functions. The whole protein composition also makes this artificial skin essentially different from other existing color-tunable artificial skins, which are a combination of organic and inorganic compounds. Furthermore, because the protein composition is compatible with a range of dyes, the chromatic gamut of adaptive coloration of the developed artificial skin can be further expanded by color fusion. With the further inclusion of other functional units, such as photothermal and magnetothermal nanoparticles, the thermochromism of the artificial skin could be realized through sun exposure and alternating magnetic field modulation. With this diversity in color change pathways and stimulation mode, as well as the environmental friendliness of the material used, these artificial proteinic skins have promising applications as sensors in physiological monitoring, food preservation, and anti-counterfeiting.