Nano-scale optical elements by fine patterning of self-assembled monolayers

本项目是关于使用微接触印刷(UCP)制造纳米级光学元件的方法。将烷基硅烷分子涂覆在聚二甲基硅氧烷(PDMS)邮票上，形成纳米到微米级的图案，然后将分子转移到玻璃晶片上形成自组装单分子膜(SAM)。然后，用荧光分子标记分子以增强光学性质。我们用PDMS作为邮票的材料。采用各向同性刻蚀或电子束直接光刻的硅模转移印章图案，首先利用具有微尺度线条和间距的印章验证SAM图案化的可行性。我们将末端带有氨基的氨基丙基三乙氧基硅烷(APTES)涂覆在PDMS邮票上，并将邮票压制在玻璃晶片上。用荧光染料分子(FITC)标记图案化的APTES，并在荧光显微镜下观察。通过比较邮票和图案化的APTE的线宽来评估图案。对于合适的图形，压制时间和压力分别为15秒和20克。其次，制备了纳米级光学元件。FITC本身被用作光学元件。将APTES的纳米图案化与FITC标记相结合，成功地实现了纳米级光学元件的制备。利用用亚微米线条绘制的插图的PDMS邮票，APTES被刻画在玻璃晶片上。FITC结合到图案化的APTE上。我们成功地观察到荧光分子确实以纳米级的分辨率沿着APTES构图，并证实了荧光分子作为纳米级光学元件的作用。

This project is on a fabrication method of nano-scale optical elements using micro contact printing (uCP). Alkyl silane molecules were coated on poly(dimethylsyloxane) (PDMS) stamps with nano- to micro-patterns, and transferred the molecules onto a glass wafer to form a self-assembled monolayer (SAM). Then, the molecules were labeled by fluorescent molecules to enhance optical properties. We used PDMS as a material of the stamps. The patterns of the stamps were transferred from silicon molds, which were fabricated with isotropic etching or electron beam (EB) direct lithography.Firstly, stamps with micro-scale lines and spaces were used to confirm the feasibility of SAM patterning. We coated Aminopropyltriethoxysilane (APTES), which has amino group at its terminal, on the PDMS stamps, and pressed the stamp onto glass wafer. The patterned APTES were labeled by the fluorescent dye molecules (FITC), and observed with fluorescent microscope. The pattern was evaluated by comparing the line width of the stamps and the patterned APTES. For suitable patterning, the pressing time and pressure were found to be 15 seconds and 20 grams, respectively.Secondly, nano-scale optical elements were fabricated. The FITC itself was used as an optical element. Combining the nano-scale patterning of APTES and the FITC labeling, we successfully achieved to fabricate nano-scale optical element. Using PDMS stamps of an illustration, which was drawn with sub-micron lines, APTES was patterned on a glass wafer. The FITC were bound to the patterned APTES. We successfully observed that the fluorescent molecules were surely patterned along the APTES with nano-order resolution, and confirmed that the fluorescent molecules work as nano-scale optical elements.