IR-inspired visual display/response device fabricated using photothermal liquid crystals for medical and display applications

Combined applications of composite materials are very important in today's science, especially those of liquid crystal (LC) materials. Visualization of near-infrared (NIR) with zero power consumption using a combination of photothermal and LC materials is urgently needed. In this study, a device was constructed from thermosensitive cholesteric LC (CLC) and nano-level polypyrrole materials, and named a photothermal polypyrrole nano-pigment-integrated with CLC (PNCLC) display element. A change in the reflected light of the CLC display element was achieved by the photoabsorption-exothermic characteristics of polypyrrole, which absorbs NIR light to drive the photothermal performance. The temperature and color change caused by the absorption of NIR light resulted in the CLC display element automatically indicating a change in the NIR intensity. In addition, to increase the range of potential applications, conductive soft polyethylene terephthalate (PET) substrates were used as display elements. To the best of our knowledge, this is the first study to illustrate a visual display element of NIR light intensity with zero power consumption and explore its potential theranostic applications.