| 초록 |
Colloidal photonic crystals (CPCs) are very useful for a variety of photonic-crystal applications due to their tunable photonic band gap and easy manipulation of optical properties. CPCs can be fabricated either by forming opal structures on a flat substrate or by using droplets as a template. The former can be demonstrated as a form of free-standing film, however, it disadvantageously exhibits angle-dependent structural colors. In contrast, the latter suffers from processibility, despite its outstanding optical property of angle-independent single color. To overcome this incompatible challenge, here, we present a synergistic means of fabricating flexible free-standing films of CPCs while retaining angle- and strain-independent characteristics using a microfluidic device system. Furthermore, the shape and crystallinity of the inner droplets inside double emulsions can be tuned by osmotic annealing, which depends on the osmotic pressure difference between the inner and outer phases. |
