The Electrical-Triggered High Contrast and Reversible Color-Changing Janus Fabric Based on Double Side Coating

A sensitive electro-thermochromic Janus fabric driven by voltage is demonstrated via a facial double side coating. The graphene forms a conductive layer that allows Joule heating to supply the thermal resource for the electro-thermochromic behavior of polyester fabric. The thermochromic dye with reversible color-changing property is coated on the opposite side of the graphene layer. The color of electro-thermochromic Janus fabric changes from blue to white with a gradual heating that exceeded 45 °C at the applied voltage of 10 V. The switching rate of color is rapid with the increase of temperature from the room temperature to above 45 °C in 8 s, resulting from the superior resistive heating of the graphene. The electrical conductivity of the electro-thermochromic Janus fabric is not disturbed once undergoing a bending angle range from 30° to 150° and the temperature remains stable after 1000 bending cycles which clearly indicates the excellent flexibility of the fabric. The steady signal in the heating/cooling curve is observed after 500 cycles, pointing out the outstanding durability of the electro-thermochromic Janus fabric under the supplied voltage. It is realizable that the color of electro-thermochromic Janus fabric is triggered accurately by varying the supplied voltage. The simplicity of this design makes it attractive for the application of flexible electro-thermochromic textile, such as active visual camouflage, personal thermal management, and information displays.