Liquid Metal Printed Optoelectronics Toward Fast Fabrication of Customized and Erasable Patterned Displays

Abstract Display devices show great application prospects in various fields. Among them, the flexible display which can quickly produce customizable patterns has attracted the attention of researchers. In this study, two types of electroluminescent devices, which introduce liquid metal printed patterns as the electrodes for electrical input, are proposed, theoretically analyzed, and experimentally characterized. One type is to stack the liquid metal electrode, the emissive layer and the transparent electrode in a sandwich configuration. The other is to construct two patterned liquid metal electrodes on one side of the emissive layer and then emit light from the edge of the liquid metal patterns. Compared with the traditional materials, the liquid metal can be quickly patterned so that the obtained liquid metal electroluminescent devices can display customized and erasable luminous patterns. This new display device is easy to access in virtue of various liquid metal printed methods. For practical illustrations, a wristband for monitoring human body temperature and a programmable 8 × 8 pixels flexible screen with double layer liquid metal printed circuits are further designed and demonstrated. This study opens the door to quickly fabricate personalized displays in low quantities based on liquid metal and shows significant potential in flexible electronics.