Highly Ordered Microstructures Fabricated By Microcontact Printing Technique

Fabrication of patterned surface in micro/nano scale has important scientific significance for the development of modern science and technology.The development opportunity of many electronic and optical devices relies on the successful fabrication of new microstructures and the miniaturization of current structure.Controllable fabrication of ordered microstmctures is the essential prerequisite of device construction of various modern materials.Meanwhile,patterning of functional materials into micro/nano structures may bring surprising phenomena and new functionalities.Therefore,new technologies for surface patterning of functional materials have always attracted great attentions.In this thesis,highly ordered surface microstmctures of several functional materials are fabricated by new methods combining microcontact printing with other techniques.The new methods developed in this thesis provide flexibility for patterning a variety of functional materials into micro/nano arrays in a highly controlled manner.1.Alternating hydrophobic and hydrophilic stripe patterns were fabricated on Au substrates using microcontact printing.PS/PVP polymer blend solutions were drop-cast onto the patterned surface to give phase separation pattern on the substrates.The effects of various factors on the formation of phase separation patterns have been investigated and the optimum condition for the pattern replication has been discussed.Furthermore, we demonstrated that this phase separation technique could be used to organize functional materials,such as CdSe nanoparticles and fluorescent organic dyes Alq3,into highly regular patterns.2.Highly regular water droplet array templates were fabricated by combining microcontact printing with "breath figure" technique.Using these templates,highly ordered CdSe QDs ring arrays can be obtained.Multicolor CdSe/CdTe arrays were also prepared using the ordered CdSe QDs arrays as templates.The influences of various factors such as solvent type,solution concentration and operation procedure on the pattern quality were investigated.The key step for the fabrication technique is that the QDs behave like surfactant and are self-assembled at the water/solvent interface. 3.Patterned films of magnetic FeNi alloy were obtained by combining microcontact printing with electrodeposition.The magnetic properties of the patterned FeNi film were studied,The patterned FeNi films show both plane anisotropy and in-plane anisotropy due to the strong shape anisotropy of the FeNi stripes.