Rapid and stable temperature control is essential for efficient polymerase chain reaction (PCR) amplification. Thermoelectric cooler (TEC)-based PCR thermal cycling systems are widely used in portable and point-of-care devices because of their bidirectional thermal control and compact structure. This study aims to summarize temperature sensing and closed-loop control technologies in TEC-PCR systems.
This paper examines thermal inertia, nonlinearity, indirect temperature measurement and structural coupling under rapid thermal cycling, based on thermodynamic analysis and literature review. It compares the dynamic characteristics and uncertainty sources of different layout designs and temperature sensing strategies. Considering model dependency, computational complexity and robustness, it systematically evaluates classical proportional integral derivative (PID), segmented PID, fuzzy control, feedforward–feedback control, model predictive control and data-driven methods and discusses their engineering applicability and limitations in portable TEC-PCR systems.
The findings show that thermal coupling pathways and sensor placement have a significant impact on closed-loop stability and temperature measurement accuracy. An ideal balance between control performance, implementation complexity and reliability is reached by the enhanced PID control. Although data-driven and model predictive approaches have the potential to handle nonlinearities, they are nonetheless limited by processing power and model generalization skills in portable systems. Heating/cooling rates, temperature consistency and system energy efficiency are all fundamentally supported by the thermal management framework.
By integrating temperature sensing, closed-loop control and thermal management into a unified framework, this review provides a systematic perspective on TEC-PCR thermal cycling technologies, offering valuable guidance for the design and optimization of portable nucleic acid amplification systems.
