Study On A Novel PCR Chip Applied To Biomedical Detection

Bio-chip is a new interdisciplinary field with the combination of micro-processingtechnology and biotechnology. PCR bio-chip has become a research focus because ofthe advantages that traditional PCR do not have, such as low power consumption, lowcost, simple operation, easy integration, and so on. In this paper, a new PCR chip andsystem, which applied to biomedical testing, are presented based on learning progressof this field. Upon completion of chip layout design, fabrication and experiments test,processing condition of two kind of new polymer, which are promising applied tobio-chip fabrication, is investigated at the same time. The main structure of this paperis as follows.（1） two edition PCR chip systems are proposed, and the functional components andthe overall layout of the chip are designed. A three-module PCR micro chip system isproposed in the design of the first edition chip. A novel PCR chip system is developedbased on the improving of the the first edition chip. With consideration ofcompatibility with micro processing technology and parameters comparison ofalternative materials, the chip substrate material and the functional componentsfabrication material are selected. Temperature sensors and various morphologymicro-heaters and micro-electrodes are designed on the basis of parameterscalculation and comparison.（2） the fabrication process and results of PCR chip and the assembly of microsystems are well introduced. The chips are fabricated with MEMS micro-processingtechnology. It can be seen from the processing result characterized by optical andSEM photographs that the thickness of films on chip surface is uniform, the lines offunctional devices are clear, and the processing result is excellent.（3） a series of experiments proceed on the basis of packaged chips in order to testthe performance of the chip. It is measured that the temperature sensor TCRcoefficient is4.34×10^-3℃^-1, and the chip has excellent thermal uniformity and goodaverage speed of heating and cooling, which are3℃/sand5℃/s, respectively. Thechip can also carry out PCR temperature cycling with good temperature stability andwell control. It is obtained that the detection limit of the micro-electrodes for DNA is6.9×10-10mol/L, and the micro-electrodes has high sensitivity, good stability andrepeatability. （4） a C4F8-based reactive ion etch （RIE） process is developed to dry etch the siliconelastomer polydimethylsiloxane （PDMS）, which obtained optimized experimentalconditions and excellent result and provide a alternative method to resolve theproblem that PDMS hard to be patterned directly when it used for fabricatingbio-microfluidic systems.（5） exposure and development characterization of a novel acrylate basedphotopolymer dry film photoresist （DFP） is presented. And micro-channel isfabricated on-chip with the DFP is investigated. The processing conditions of DFPexposure and development are optimized and obtained micro-fluidic channelstructures with excellent morphology.