Fbrication Of Polymer Based Continuous Flow PCR Chip By Excimer Laser And Its Applicaiton

The development history, the present status and the future trend of biochip is systemly summarized firstly in this paper, then the important status in the history of biochip and the research significance of continuous-flow PCR chip are pointed out. After that, the oversea and inland research status about continuous-flow PCR chip is studied carefully, and the existent problems and solution about it are induced. It means that the cheap polymers are chosen as the substrates, and a 248nm excimer laser with flexible and automatic characters is selected as a new micro-fabrication technique.The most important problem of continuous-flow PCR chip is the transition length computation of temperature or velosity distribution from inlet to steady status. However there are no numerical computations about continuous-flow PCR chip. So the microfliudic velosity and temperature distribution in direct microchannel, curve microchannel and widing microchannel with 100μm width and 50μm depth are computated using FLUENT software. The transition lengths of microfluid from inlet to steady status are discussed. Then based on the principle for PCR, 20-cycle continuous- flow PCR is designed using CAD software.To the designed 20-cycle continuous-flow PCR chip, a KrF excimer laser (direct write method) is adopted as the fabrication technology, and the polymethyl methacrylate (PMMA) is selected as the substrate. So the appearances of PMMA surface etched before and after by 248nm excimer laser under different incident fluences are analyzed using SEM. Furthermore, the etching rate, roughness versus incident laser fluences and pulse number are investigated theoretically and experimentally in detail by 3D surface analyzer. Then a new priciple of PMMA etched by excimer laser is given: the process is the interaction result of photodecomposition,...