热电冷却微流体芯片的温度响应特性优化研究

Optimization of Temperature Response Characteristics for Thermoelectric Cooling Microfluidics

精确的温度调控是微流体技术在生化分析和医学诊断等方面发展应用的重要保障。为实现微流体芯片目标区域的温度控制,本文设计了基于异型结构热电制冷器的微流体芯片温度控制系统,通过数值模拟和实验测试分析了该温控系统的传热特性及及温度响应特性。研究结果表明:采用的热电制冷器可将微流体芯片样品池的温度降至-24℃,但样品池的降温速率远小于热电制冷器的冷端降温速率,存在温度响应迟滞问题。为此,进一步提出了带有聚冷结构的系统优化,结果表明:聚冷结构的引入虽然会带来少量的冷量损失,但可以显著提升该温控系统的温度响应速率,有效减少响应时间。对于T型聚冷结构,当下底直径为14 mm和10 mm时,可分别将温度响应时间减少30%和40.7%。

Precise temperature control is needed for developing and applying microfluidic technology in biochemical analysis and medical diagnosis.A temperature control system based on a thermoelectric cooler with a specially shaped structure was designed to realize the temperature control of the target area of microfluidic chips.The heat transfer and temperature response characteristics of the temperature control system were analyzed based on numerical simulation and experimental tests.The results showed that the thermoelectric cooler reduced the temperature of the sample cell of the microfluidic chip to-24℃.However,the pull-down rate of the sample cell was much lower than that of the thermoelectric cooler,which exhibited temperature response hysteresis.To address this challenge,a T-shaped concentrated cooling structure was proposed.The results showed that the concentrated cooling structure substantially improved the response rate of the temperature control system and effectively reduced the response time,at a cost of consuming a small amount of cooling.For the concentrated cooling structure with a lower diameter of 14 mm and 10 mm,the temperature response time was reduced by 30%and 40.7%,respectively.