A research team at the Ningbo Institute of Materials Technology and Engineering (NIMTE) of the Chinese Academy of Sciences (CAS) has developed a flexible near-infrared (NIR) light-writing multicolor hydrogel system for an on-demand information display.
Intelligent rewritable display systems have long been expected to reduce the heavy consumption of single-use or transient devices in the Internet-of-Things (IoT) age. It shows great potential in alleviating environmental pollution and resource consumption resulting from the increasing disposable electronic waste. However, it remains challenging to construct such systems with integrated functionality of remote control, rapid activation, multicolor and multimode display.
The distinctive vertical configuration of multilayered chromatophores in chameleon skin contributes to the reversible and multicolor pattern display. Inspired by this intricate structure of chameleon skins, researchers at NIMTE developed a novel, flexible, near-infrared (NIR) light-triggered rewriteable multicolor hydrogel system capable of displaying data on demand.
The hydrogel system adopts a vertically arranged multilayer structure, which consists of a fluorescent hydrogel layer as the display unit and an efficient poly(dimethylsiloxane) (PDMS)-sealed carbon nanotubes (CNTs) film layer as the control unit.
Within the fluorescent hydrogel layer, a thermo-responsive fluorescent hydrogel as the inner core is constrained within a non-responsive hydrogel, thus facilitating stable, reversible, and multicolor information loading.
The system operates on a cascading process of the “light trigger–heat generation–fluorescence output” process. This allows the user to hand-written and displays arbitrary information, like numbers and letters, within 5 seconds using NIR light as a pen. The data can be self-erased for another rewriting cycle within 36 seconds.
In addition to the light-writing display of transient information, this bio-inspired multilayer structure design has been demonstrated to facilitate the easy patterning of both the photothermal CNT layer and the fluorescent hydrogel display layer, realizing the sustainable light-projecting display of multicolor patterns.
This fluorescent hydrogel rewritable display system helps to meet the diverse information display or transmission requirements, improves information visualization effect and interactive experience, and may shed light on the further development of the light-writing system.
- Shuxin Wei, Wei Lu, Huihui Shi, Shuangshuang Wu, Xiaoxia Le, Guangqiang Yin, Qingquan Liu, Tao Chen. Light-Writing and Projecting Multicolor Fluorescent Hydrogels for On-Demand Information Display. Advanced Materials, 2023; DOI: 10.1002/adma.202300615