A thermosensitive poly(N-isopropylacrylamide) (PNIPAM) circular gel film containing single-crystalline colloidal crystals was prepared, and the circular edge was pinched with washers to restrain the in-plane shrinkage of the gel film. Upon heating, the film shrunk in the thickness direction selectively, resulting in a change in the crystal structure of colloids embedded in the anisotropic shrunken gel. This led to the manipulation of the optical stop-band wavelength of the colloidal photonic crystals with a higher thermosensitivity and over a wider range of wavelengths covering a wide margin on either side of the visible-light region. The present method for enhancement of the sensitivity is very simple, and the principle should also be applicable to the gel-immobilized colloidal crystals that respond to stimuli other than temperature changes. The present findings contribute to the progress of practical applications of gel-immobilized colloidal photonic crystals as tunable photonic crystals and biological and chemical sensors.

中文翻译：

---

具有各向异性收缩的凝胶固定可调谐胶体光子晶体的热敏性增强

一种热敏聚( N制备含有单晶胶体晶体的-异丙基丙烯酰胺(PNIPAM)圆形凝胶膜，并用垫圈夹住圆形边缘以抑制凝胶膜的面内收缩。加热时，薄膜在厚度方向选择性收缩，导致嵌入各向异性收缩凝胶中的胶体的晶体结构发生变化。这导致对胶体光子晶体的光学阻带波长的操纵具有更高的热敏性和更宽的波长范围，覆盖可见光区域两侧的宽裕度。本发明提高灵敏度的方法非常简单，该原理也应该适用于对温度变化以外的刺激有反应的凝胶固定胶体晶体。