Some butterfly species such as the orange oakleaf (Kallima inachus) have strikingly different colors on the dorsal (front) sides of their wings compared to those on the ventral (back) sides of their wings, which helps camouflage the butterflies from predators and attract potential mates. However, few human‐made materials, devices, and technologies can mimic such differential coloring for a long time. Here, a new type of Janus‐structured two‐sided electrochromic device is developed that, upon application of different voltages, exhibits a coloration state on one side that is distinctly different from that on the other side. This is achieved by inserting an optically thin (4–8 nm) metallic layer with a complex refractive index, such as a layer composed of tungsten, titanium, copper or silver, into typical electrochromic structures.
The fiber-shaped Ni–Fe battery takes advantage of high capacity of hierarchical CoP@Ni(OH)2 NWAs/CNTF core–shell heterostructure and spindle-like α-Fe2O3/CNTF electrodes to yield outstanding electrochemical performance, demonstrating great potential for next-generation portable wearable energy storage devices.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.