Color-transparency dual-control devices based on patterned electrode-induced limited assembly of photonic liquid

Abstract

Due to the fine and fast control of color or transparency, electroresponsive smart optical materials are increasingly in demand in the fields of camouflage, display, and energy-saving buildings, etc. However, it is still a great challenge to achieve the dual control of color and transparency. Here an effective strategy is proposed based on the limited assembly of an Fe₃O₄@C photonic liquid induced by a patterned electrode. This electroresponsive device could achieve a color change from orange-red to blue and a transparency change from opaque to translucency (7%–46%), attributed to the modulation of the colloidal lattice spacing at low voltage and patterned electrode-induced segregation at high voltage. A suitable concentration of NPs (12%) was optimized based on a balance between an ordered assembly and segregation of moderate NPs. Moreover, the effect of the electrode's pattern structure on the limited assembly of colloidal NPs was also studied. Our work provides an effective strategy for the design of electroresponsive photonic liquids and broadens their potential applications.