3D‐Printed Hydrogel‐Based Flexible Electrochromic Device for Wearable Displays

• Published in: Advanced science Vol. 11; no. 38; pp. e2404679 - n/a
• Main Authors: Luo, Xiaoyu, Wan, Rongtai, Zhang, Zhaoxian, Song, Manting, Yan, Lixia, Xu, Jingkun, Yang, Hanjun, Lu, Baoyang
• Format: Journal Article
• Language: English
• Published: Germany John Wiley & Sons, Inc 01.10.2024; John Wiley and Sons Inc; Wiley
• Subjects: 3-D printers; 3D Printing; camouflage; Electrodes; Electrolytes; Electrons; flexible electrochromic device; Hydrogels; Optimization; Polyvinyl alcohol; Screen printing; wearable displays; 3D Printing; wearable displays; hydrogels; camouflage; flexible electrochromic device
• ISSN: 2198-3844; 2198-3844
• DOI: 10.1002/advs.202404679

Flexible electrochromic devices (FECDs) are widely explored for diverse applications including wearable electronics, camouflage, and smart windows. However, the manufacturing process of patterned FECDs remains complex, costly, and non‐customizable. To address this challenge, a strategy is proposed to prepare integrated FECDs via multi‐material direct writing 3D printing. By designing novel viologen/polyvinyl alcohol (PVA) hydrogel inks and systematically evaluating the printability of various inks, seamless interface integration can be achieved, enabling streamlined manufacturing of patterned FECDs with continuous production capabilities. The resultant 3D‐printed FECDs exhibit excellent electrochromic and mechanical properties, including high optical contrast (up to 54% at 360 nm), nice cycling stability (less than 5% electroactivity reduction after 10 000 s), and mechanical stability (less than 19% optimal contrast decrease after 5000 cycles of bending). The potential applications of these 3D‐printed hydrogel‐based FECDs are further demonstrated in wearable electronics, camouflage, and smart windows. The manufacturing process of patterned flexible electrochromic devices (FECDs) complex and non‐customizable. To address this challenge, a strategy is proposed to prepare integrated FECDs via multi‐material direct writing 3D printing. The FECDs exhibit impressive electrochromic and mechanical properties, including high optical contrast and excellent cycling stability, and is shown to have great potential in wearable displays, camouflage, and smart windows.