The Research Of Temperature Control System For PCR Chip Based On Labview

With the development of the society,People demand more and more on health and life, so the importance of disease prevention and early detection is getting higher and higher. Every county put a lot of power and money into researching and developing test equipment. All kinds of large testing equipment appear in each major medical institution. In compared to the expensive and large equipment, microfluidic chip is a chip of rapid expansion to the genes and detection. It's is tiny, and low prices, reaction quickly. It could make target gene amplified thousands of times in only a few hours or in a few minutes, in order to test.PCR microfluidic chip is the application of MEMS technology in the biological and chemical analysis. It combines the traditional PCR (the polymerase chain reaction) and the advanced MEMS technology, making all the biological reaction in a chip. Based on the laboratory research experiences, we design and develop a kind of PCR-CE chip. On the basis of LabVIEW , a temperature control system for the PCR chip is designed and developed. The temperature system uses PT as resistive heater and temperature sensor, and uses CPU Quiet Fan and Semiconductor Refrigeration Piece as the cooling equipment.The main research contents and results are as follows:1. State the concept and classification of MEMS. Microfluidic chip is a big application in biology of MEMS. Give a pellucid introduction to PCR and CE chip,and analyze the current research situation PCR temperature control system at home and abroad.2. Design a kind of PCR-CE integration chip, and do simulation in contrast with the past design. Results show that the new design has got obvious improvements both in integration and temperature control. Develop a high efficient, low cost of processing technology tonew design scheme. Adopting soft lithography method,we make a PDMA cover piece with the reaction chamber and micro channel. Form the Pt electrode in glass substrate using dry etching. And then dump a layer of PDMS glue on the top of platinum electrode, and bond with the PDMS cover.3. Design a temperature control system according to the PCR-CE made chip, including the power supply module, temperature acquisition module, signal amplifier module, chip warming and cooling module and the data acquisition module. Through the analysis of resistance measurement method, the constant source incentive temperature acquisition circuit is chosen, and make the error analysis.4. Introduce the graphic programming LabVIEW, write the temperature conversion program and temperature control procedures, and design a friendly user interface.5. Debug the temperature control system. First, calibrate the Pt resistance; Next filter the circuit noise; calibrate the parameters of software control, and amend the original control strategy. The entire system begins to run in a normal state.The temperature control system that this paper designs has the following advantages:1. Accurate temperature acquisition, with acquisition accuracy of 0.1℃;2. The temperature rises fast, stable speed, can be in 1 s realized in two different temperature of switching; the system can realize switching in two different temperatures in 1 s;3. With a good human-machine interface, the operation is simple and easy to operate, and biological researchers who don't understand of temperature control can also be convenient to use.