For on-demand information display, scientists headed by Prof. Tao Chen at the Ningbo Institute of Materials Technology and Engineering (NIMTE) of the Chinese Academy of Sciences have built a flexible near-infrared light-writing multicolor hydrogel system.
Multicolor fluorescent hydrogel system with biomimetic vertical multilayer structure for on-demand information display. Image Credit: NIMTE
In the Internet-of-Things era, the development of smart rewritable display systems is likely to minimize resource consumption and environmental pollution resulting from the increasing quantity of disposable electronic waste. They are likely candidates for medium for information transmission and display.
Nevertheless, it is still difficult to build such systems while integrating different functionalities, including rapid activation, remote control, multimode, and multicolor display.
The special vertical arrangement of multilayered chromatophores creates the reversible and multicolor pattern displayed in chameleon skin. For on-demand information display, the scientists built a novel flexible NIR-light-triggered rewritable multicolor hydrogel system that is inspired by this skin.
According to scientists, the hydrogel system is in a vertically arranged multilayer structure comprising an effective poly(dimethylsiloxane) (PDMS)-sealed carbon nanotubes (CNTs) film layer as the control unit and a fluorescent hydrogel layer as the display unit.
The inner core of a thermo-responsive fluorescent hydrogel is limited within a non-responsive hydrogel in the fluorescent hydrogel layer, thereby enabling reversible, stable, and multicolor data loading.
Through the cascading process of “light trigger-heat generation-fluorescence output,” arbitrary data like letters and numbers could be hand-written and displayed in less than 5 seconds with the use of NIR light as a pen and self-erased for another rewriting cycle in less than 36 seconds.
Besides the light-writing display of transient data, this bio-inspired multilayer structure design was established to enable the seamless patterning of either the photothermal CNTs layer or the fluorescent hydrogel display layer, therefore recognizing the sustainable light-projecting display of multicolor patterns.
This fluorescent hydrogel rewritable display system aids in fulfilling the different needs of information transmission or display, enhances the data visualization effect and interactive know-how, and might throw some light on the developments of the light-writing system.
This study was aided by the National Key R&D Program of China, National Natural Science Foundation of China, Zhejiang Provincial Natural Science Foundation of China, etc.
Journal Reference
Wei, S., et al. (2023). Light‐Writing & Projecting Multicolor Fluorescent Hydrogels for On‐Demand Information Display. Advanced Materials. doi.org/10.1002/adma.202300615.