Design Evaluation and Numerical Study of Micro-Heating for a Microfluidic Loop-Mediated Isothermal Amplification

The emergence of COVID-19 highlighted the urgent need for rapid and accurate diagnostic tools. Loop-mediated isothermal amplification (LAMP) has gained significant attention for its rapidity, simplicity, and cost-effectiveness, especially for point-of-care testing. However, precise and uniform temperature control in micro-heating systems remains challenging, limiting the portability of conventional LAMP assays. This study addresses these challenges by designing and simulating a micro-heater optimized for low power consumption and high temperature uniformity. Utilizing multiphysics simulation software, we modeled the heating element with variable voltage differences to achieve the precise temperature distribution required for LAMP processes. Our results show that at a voltage of 0.3V, the micro-heater achieved temperatures of 41°C in 1 minute and 51°C in 60 minutes, closely matching simulation predictions. The microfluidic device successfully integrated the micro-heater, achieving uniform temperature distribution with minimal variation of 1.5°C across the chip. Experimental validation confirmed the micro-heater's effectiveness, demonstrating rapid and uniform heating with low power consumption. These findings enhance the reliability and efficiency of LAMP-based assays, making the design suitable for portable diagnostic tools. This innovation is crucial for developing cost-effective diagnostic tools for resource-limited settings, contributing significantly to efficient disease management and surveillance.