Microchannel Hot Forming Temperature Control System

With the extensive application of microfluidic chips in biochemistry, analytical chemistry and other fields, realization automation and volume-production of the fabrication for microfluidic chips have been the consequential tendency. In this dissertation, based on the analysis of the development of the fabrication technology for microfluidic chips, a temperature control system has been developed, which is based on thermoelectric module for fabricating plastic microchannel by hot embossing. The performance of the temperature control system has been analyzed and validated by experiments.Plastic microfluidic chips fabrication technology and the temperature control systems for hot embossing were summarized. The flow behavior of plastic substrates used for hot embossing lithography and the effect of temperature for fabrication quality of microchannel in hot embossing process was narrated. The following is the main content:The scheme of system was investigated. The thermoelectric module as heat/cooling element and circulating-water-assisting cooling were employed in temperature system. By analyzing the characteristic of the thermoelectric module, the power of heating/cooling in hot embossing was calculated, the number and type were determined.The mechanism had been designed. Based on the hot embossing technology and the requirement of installation of TE module, the method that heating plate components and cooling-tank components were correspondingly separated was adopted. Its' configuration, fabrication technique and precision requirement were designed. The methods of installation and regulation were explained.The computer control system had been designed and developed. Pt100 as the temperature sensor, temperature signal conditioning module, I/V signal conditioning module, A/D converter were collocated. Commence on the parameter of four TE module in series, the power unit was developed, which power can be adjusted by ON/OFF time from I/O signal and current direction can be controlled by relay signal, both signal are output from computer.Test had been done. Experiments include the rising/falling speed, temperature control accuracy and temperature distributing uniformity. The result show, the rising/falling speed exceed the requirement 0.5C/s and 0.3C/s respectively. The accuracy of temperature control is +0.2C. Actually, in steady state, during operation in hot embossing, the temperature deviation in the part of chip is less than +0.1C.The system has been applied to fabricating microfludic chips. The effect indicated that the system is reliable and satisfies the requirements of temperature control in hot embossing.