Study On Micro Transfer Molding Of Soft Lithography In Micro Total Analysis Systems

Micro total Analysis Systems (μ-TAS) is the important direction of analysis instruments. It integrates the experimental sample preparation, biochemical process and result measure on single chip for certain analytic purposes. In recent, with the development of lithography tech, micro fabrication tech and CAD tech, the fabrication of some elaborate micro structures turns to much easier, and the expense of the fabrication decreases gradually too, which make the commercialization of the μ-TAS possible. Although various strongpoint μ-TAS have, the industrialization still confronts a lot of obstacle, especially a series of feasible technique for the system fabricating and assembling.As a newly coming micro fabrication technology, soft lithography use elastomeric stamp to replace hard stamp in traditional Lithography to fabricate micro patterns and structures. Compared with traditional Lithography, soft lithography has several advantages. Firstly, it can fabricate complicated 3D structure even on irregular substrate. Secondly it can apply in multi materials and chemical surfaces. In addition, it can overcome the 100nm obstacle of lithography, and realize much more elaborate micro fabrication.Now, Soft Lithography is widely applied in various fields including the fabrication Optics, Biotechnology, Microelectronics, Sensors and μ-TAS. This paper will emphasize on the application of soft lithography in the fabrication of μ-TAS. The paper introduces the basic theories and pivotal technologies of soft lithography systematically, especially the PDMS, which acts as the basic material of the fabrication, and discusses its applications, feasibility and general technological scheme in μ-TAS detailedly. Then, according to the μ-TAS of the Deformation of Red cell, one of the project our group concentrated on, we select micro transfer molding (μTM) to fabricate the Si micro channels chip, which is also the core of the total system. Basing on the research, the paper set up total techniques for μTM, including copy the micro structure from Si chip using PDMS and transfer the micro structure onto the glass substrates, and indicated the things should be paid attention to during the procedures. Then, the paper found a best temperature and pressure model, according to the factors which can determine the quality of the fabrication. Finally, benefited from the analysis part of Coventorware, we prove the performance of PU micro channels compare favourably with the micro channels made by Si in terms of microfluidics.