原子力顯微鏡修飾液晶配向膜表面之研究

Abstract

本研究探討以原子力顯微鏡在配向膜表面修飾的各項特性。我們以顯微鏡與影像處理軟體，來進行微小配向區的的光學量測，並由不同修飾條件所得到的配向區，進行穿透率與anchoring strength的量測，得到不同修飾條件與配向效果的關係。接著利用傅氏轉換來探討液晶配向的機制。我們得到：1. 探針的修飾雖然可以讓LC配向，但不一定代表能看到溝槽；2. 探針對配向膜的修飾線密度越大，配向的越均勻、對比度越好、anchoring strength也越大；3. 探針修飾的次數越多，anchoring strength越大，但對穿透率較無影響；4. 傅氏轉換可以提供溝槽是否存在的資訊。

We study the properties of AFM-modified polyimide film for liquid crystal alignment. We measured the transmission and anchoring strength for different modifying conditions. Fourier transform in used to study the minor change in surface topography. Optical measurements are conducted under microscope and image software, which are used to read the intensity data. We conclude: (1) although it does have alignment effect, the surface topographies may not have grooves structure; (2) by increasing line density, we can get better alignment effect, including uniformity and contrast, and the anchoring strength is also increased; (3) by increasing the number of modifying times, we can get larger anchoring strength; and; and (4) we can show the groove structure from the results of Fourier transform of AFM topographies.