The Smart Polymer Materials group led by Prof. CHEN Tao at the Ningbo Institute of Materials Technology and Engineering (NIMTE) of the Chinese Academy of Sciences (CAS) developed a conceptually new photo-mechanically modulated fluorescent system, which enables the on-demand display of fluorescent patterns/information by varying the remotely controlled near infrared (NIR) signal. The study was published in Advanced Materials.  

Upon environmental stimulation, cephalopods display their dazzling skin colors/patterns efficiently via the bioelectricity-controlled muscle contraction and expansion of skin chromatophores. Soft intelligent luminescent material systems which can realize similar on-demand display of dynamic colorful patterns/information upon stimulation have gained increasing attention in diverse applications such as information encryption and dynamic camouflage.  

However, it remains challenging to develop a fluorescent display system that combines appealing features of reversibly/rapidly switchable multicolor fluorescence and remote control with high spatial/temporal precision. 

Inspired by the mechanically modulated display mechanism of cephalopods, researchers at NIMTE constructed a novel fluorescent display system that recruited mechanical actions as a mediator between two forms of radiation, i.e., NIR light and fluorescence.  

In addition to a customizable hollow display panel, this biomimetic system comprises a tri-layer fluorescent actuator, which consists of photothermal responsive carbon nanotubes, thermally expandable polydimethylsiloxanes and multicolor fluorescent glycol gels.  

Under NIR light, the photomechanically bending movements of the actuator would convert to synchronous fluorescent color/pattern substitution in the hollow window of the display panel, thus generating a time-dependent optical output from the system.  

Thanks to the desirable time- and light-power-dependence of actuating behaviors, diverse fluorescent patterns/information can be dynamically and reversibly displayed via facile control of single remote NIR signal, realizing the “single-input multiple-output” feature for the first time in the field of smart fluorescent system development.  

In addition, such photo-mechanically modulated fluorescent display system allows for a wide choice of fluorophores.  

Several interesting prototypes of fluorescent patterns/information were demonstrated, showing great application potential of the system for high-level information encryption, stretchable electronics, dynamic camouflage and intelligent color-changing soft robotics. Besides, the study may shed light on the exploration and development of more potent fluorescent display systems, advanced material stimulations and display strategies.