Electrically Driven PANI-Based Multilayer Nanocomposite Coatings for Dynamic Color Modulation

Abstract

Reconfigurable precision regulation of structural color devices is a critical step toward versatile advanced functionality and broadening application scenarios. In this work, we demonstrate the precise manipulation of red, green, and blue, three primary colors generated by the five-layer nanocomposite coatings composed of polyaniline/indium tin oxide/titanium/titanium dioxide/titanium (PANI/ITO/Ti/TiO₂/Ti). The modulation of dynamic structural colors of the proposed multilayer coatings originates from a cooperative interaction between the top PANI conductive polymer and the bottom traditional four-layer structural color consisting of ITO/Ti/TiO₂/Ti. Specifically, the three primitive colors are first achieved by three different combinations of both TiO₂ and ITO thicknesses, and then each color is modulated precisely by an intrinsic color change of the top PANI conductive layer at various voltages. As a result, the nanocomposite coatings demonstrate millisecond response time, excellent durability over 100 cycles, driving voltages below 1 V, and a wide temperature tolerance range from 5 to 60 °C. Additionally, centimeter-scale R, G, and B letter-shaped samples are fabricated using a mask plate coating technique, showcasing color modulation in patterned samples. Our work offers a straightforward strategy to realize the dynamic manipulation of the three primary colors within a certain range, which lays a solid foundation for the development of dynamic display technologies, such as dynamic paintings and e-books.