基于聚合物分散液晶的图案化柔性智能窗户

Patterned flexible polymer dispersed liquid crystal smart windows

聚合物分散液晶(PDLC)在投影显示和智能窗户等领域具有广泛的应用,将器件实现图案化和柔性化能够进一步拓展其应用场景。本文提出了一种采用单步紫外曝光的方式制备图案化的PDLC柔性智能窗户。采用PET-ITO作为柔性基板制备液晶盒,并于器件上表面放置一层有特定紫外衰减率的图案化掩膜板进行紫外固化,线宽为120μm的图案能够清晰分辨。本文对图案化器件的不同区域的电光特性进行了研究,实验结果表明采用高紫外光固化区域的PDLC具有较高的阈值电压和饱和电压。高紫外固化区域和低紫外固化区域上升时间分别为4.1 ms和15.4 ms,下降时间分别为14.1 ms和33.7 ms,满足智能窗户应用需求。通过施加不同的外加电场,该图案化智能窗户能够呈现全散射态、全透明态和图案化透明展示态3种模式。最后本文展示了器件处于平面状态和弯曲状态下施加不同驱动电压时该柔性智能窗户的展示效果。本研究表明采用上述单步紫外曝光方式制备的图案化PDLC柔性器件具有工艺简单、成本低、精度高等优势,有利于其在定制化图案的柔性智能窗户领域的广泛应用。

Polymer dispersed liquid crystal(PDLC)is widely used in projection displays,smart windows and other fields.Patterned flexible smart window based on PDLC would further expand its application.In this paper,a patterned flexible PDLC smart window is demonstrated using one-step UV exposure.The PDLC precursor is sandwiched between two flexible PET-ITO substrates,and a layer of patterned mask with specific UV attenuation is attached on the cell for UV curing.The linewidth resolution of 120μm is obtained for the proposed patterned flexible smart window.In this paper,the different electro-optic characteristics of the different regions of patterned device are studied.The experimental results show that the PDLC with high UV curing region has high threshold voltage and saturation voltage.The rising times of high UV curing region and low UV curing region are 4.1 ms and 15.4 ms,and the decay times are 14.1 ms and 33.7 ms,meeting the application requirements of smart windows.By applying different voltages,the patterned smart window can present three modes:total scattering state,total transparent state and patterned transparent display state.Finally,the pattered smart window working in plane state and bending state are exhibited in the paper.This study shows that the patterned PDLC flexible device prepared by the above one-step UV exposure has the advantages of simple fabrication,low cost and high precision,which is conducive to its potential applications in the field of customized flexible smart windows.