Fabrication Of Multi-functional Micro-Structure Of Ordered Binary Array By Multiplex Patterned Approach

Micro-structure or surface pattern has played an important role in both modern science and technology. Followed, a variety of construction techniques and methods have emerged. Developing technologies show the rich diversity and functionality in many areas, such as microelectronics, information storage, solid-state physics, materials science, biotechnology and application of fluid science and so on. However, a single pattern technology always has shortcomings or deficiencies in one way, such as laser or particle beam writing techniques. These techniques possess high precision and control capability, but they suffer complicated operation, poor general-purpose, time-consuming and expensive. By contrast, the recent emerging of self-assembly techniques can be quickly and easily construct micro-patterns, but they have less controllable and precision. For the complex binary structure, it is very difficult to fabricate by a single strategy. Accordingly, improving the existing technologies for novel pattern remain new opportunity and challenge in pattern technology. In this paper, through a combination of one or several patterned technologies, we first construct a chemical or physical patterned template. Then, by the template-induce dewetting process on the surface, variety of ordered binary microstructure array had been obtained. This policy strategy for combination of multiple patterned technologies to construct the ordered binary structures array, not only followed the advantages of each patterned technology, but also makes up for their deficiencies, which complement each other. At the same time, this multiplex strategy provides a new approach for design and fabrication of functional and structural structure array.In chapter 2, we fabricated the large-area surface with ordered binary structures via controllable dewetting of polymer thin films. Firstly, the substrate with stripe patterned resist was obtained by conventional photolithography. By chemical vapor deposition (CVD) of fluoride silane (PFS), the chemical heterogeneous substrate was fabricated. Then the polymer film was spin-coating on the patterned substrate and thermal annealing above its Tg. By regulating the simple conditions including concentration of polymer solution and pattern of PFS modification, the diverse topographies had been obtained finally. And the fabrication process were investigated and calculated in detail. The novel surfaces mimicked the natural rice leaf in surface structure. Moreover, these surfaces with ordered binary stripes exhibited well anisotropic wettability for water droplet as natural rice leaf. After a large number of static contact angle measurements, it was confirmed that the anisotropy had been influenced by the periods of the patterns. For a variety of topographies, the mimicking surfaces all exhibited the anisotropy. This technique will offer an effective new way of designing the wettability of materials, and further to design and fabricate smart controllable devices.In chapter 3, we have demonstrated a versatile method to fabricate ordered homogeneous and heterogeneous bull's-eye-like arrays on the SAMs-patterned surface of a gold substrate through a simple approach. Firstly, we constructed heterogeneous thioalcohol self-assembly monolayers (SAMs) on the gold substrate by microcontact printing (μCP). Then, we fabricated the PVK dot rings on the SAMs-patterned gold substrate by SAMs-directed dewetting; at the same time, we optimized conditions of the dot formation of different materials. Secondly, as the reservation of chemical properties on SAMs, we obtained the ordered ring arrays on the dot arrays patterned surface under the protecting of water droplets by water-droplets-directed and concentration-controlled dewetting process. Finally, the ordered bull's-eye-like structure arrays had been fabricated on the gold substrate. Since both experimental steps were relatively independent, the bull's-eye-like structure that we fabricated could be not only homogeneous but also heterogeneous. We had fabricated the bull's-eye-like structure arrays of PVK/PVK, PVK/DTQA, and PVK/Fe3O4 nanoparticles separately, and characterized the properties of fluorescence and magnetism. Accordingly, diverse material could be introduced to the current system, such as fluorescent materials, electro-conductive materials and magnetic materials as long as the simple conditions are satisfied. These heterogeneous bull's-eye-like structure arrays may have potential applications including photoelectric devices, catalytic surfaces, field emission devices and integrated magnetic, gas, and biochemical sensors.In Chapter 4, the ordered rhodamine@PVA/PVK heterogeneous double-rings-like structures array was fabricated via combining colloidal lithography technology with two steps dewetting process. For the swelling property of the PDMS elastomer, non-close-packed (ncp) silica colloidal microspheres had been obtained. Then, by the"hot pressing"method, the ncp microspheres array was transferred on the prepared rhodamine@PVA film; moreover, microspheres array was partially embedded in the film and contacted the substrate. Here, we discussed the influence of film thickness in the transfer processes. Next, through the reactive ion etching (RIE) process under the mask of microspheres array, the ring-like structures array turned up below the microspheres array. The thickness of polymer film and radius of microspheres affected the ring-like structure morphology. We investigated the relationship between the two influence factors in detail. Finally, we dipped the substrate with microspheres and ring-like structures array into the PVK chloroform solution. With chloroform volatilization, the two steps dewetting process happened on the top of microspheres and the surface of substrate respectively. Followed, the PVK ring was fabricated surround the rhodamine@PVA ring. After further RIE etching, the ordered rhodamine@PVA/PVK heterogeneous double-rings-like structures array was constructed successfully. We also proved the heterogeneous double-rings-like structure by the characterization of SEM, AFM and fluorescence spectra. These unique structures array has potential application in optoelectronics device, data storage, surface photo-catalytic and surface enhanced Raman scattering (SERS). In addition, due to its universality, this method could be extended to other materials.