Flexible strain sensors are of great importance in many emerging applications for human motion monitoring, implanted devices, and human–machine interactive systems. However, the dual-channel sensing systems that enable both strain-dependent electronic and visually optical signal responses still remain underdeveloped, but such systems are of great interest for human–machine interactive uses. Here, inspired by the mechanically modulated skin color changes of squids via muscle contracting/releasing movements, a class of mechanofluorescent and conductive hydrogel laminates for visually flexible electronics is presented. The sensing laminates consist of interfacially bonded red fluorescent hydrogel, polydimethylsiloxane and carbon nanotubes (CNTs) film. Since the densely stacked microscopic CNTs film can be precisely stretched to induce the formation of network microcracks, the developed hydrogel laminates are endowed with simultaneous fluorescence-color and resistance changes, which can function as dual-channel flexible sensors for real-time human motion monitoring. These properties make the bioinspired soft hydrogel laminate electronics quite promising in the flexible electronics field.
Han Qian,Jiazhuang Tian,Xiaozhou Jiang,Bangcui Zhang,Xueliang Li,Yanhua Yang,Shulin Gao,Lin Shao,Fumin Li
To further explore the relationship between aryl substituents and mechanofluorochromic (MFC) behaviors, four salicylaldimine-based difluoroboron complexes (ts-Ph BF 2 , ts-Ph-NA BF 2 , ts-2NA BF 2 , and ts-triphenylamine [TPA] BF 2 ), including aromatic substituents with different steric hindrance effects, were designed and successfully synthesized. Four complexes with twisted molecular conformation displayed intramolecular charge transfer and aggregation-induced emission properties. Under external mechanical stimuli, the as-synthesized powders of ts-Ph BF 2 , ts-Ph-NA BF 2 , and ts-TPA BF 2 exhibited redshift fluorescence emission behaviors, and ts-Ph BF 2 and ts-TPA BF 2 could be recovered to original shifts by fuming, but ts-Ph-NA BF 2 displayed irreversible switching. ts-2NA BF 2 had no change during the grinding and fuming processes. The results indicated that the MFC behaviors could be attributed to the phase transformation between the well-defined crystalline and disordered amorphous states by X-ray diffraction measurement. Further research illustrated that ts-TPA BF 2 with the most significant MFC phenomenon could be applied in data security protection in ink-free rewritable paper.
危险品化学品经营许可证（带存储）