| PCR(Polymerase Chain Reaction)is an important means for nucleic acid amplification and detection.PCR chip is the combination of PCR technology and biochip technology and it has overcome the disadvantages of traditional PCR such as easy to be polluted,high reagent consumption and high cost.PCR chip has greatly accelerated the development of PCR technology and it has been widely used in the fields of food safety monitoring,disease prevention and environment protection.However,the complicated structure and the high cost of fabrication process and materials make PCR chip difficult to mass production and promotion.In this paper,a high throughput low-cost PCR chip and a heater chip based on MEMS and a large area precise temperature control system were designed.The PCR chip which consisted of glass and PDMS was fabricated by oxygen plasma bonding process.The heater chip which consisted of silicon substrate and platinum were fabricated by sputtering,lithography,ion milling and resist removing.In order to get the optimal structure of the heating coil,the COMSOL Multiphysics was used to simulate the temperature distribution of the heating coil surface.The design of large area precise temperature control system consisted of hardware circuit design and software design.The hardware circuit system included microcontroller circuit,heating and cooling control circuit,signal acquisition circuit,signal amplification circuit,analog to digital conversion circuit and data transmission circuit.The software design included the design of the whole process of the software and the temperature control algorithm.In this study,the formula of position PID algorithm was used.The test of the line width and resistance value of the heater chip indicated the fabrication process was feasible and repeatable.The temperature control experiment indicated that the heating rate of the system was about 2.2?/s,the cooling rate was about 2.4?/s and the steady-state accuracy of the temperature was about ±0.5?. |
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