Research on Shape-Controllable Localized Heating Method Driven by Digital Microfluidics

The localized heating technique, which minimizes high-temperature impact on thermally sensitive components and reduces impurity dispersion during encapsulation, has become a focal point in MEMS packaging research. In this study, we propose a method for localized heating at specific positions and shapes. A localized heating device, based on distributed electric field control, is constructed, where a polymer droplet on the lower substrate electrode is driven into a liquid column under the influence of a distributed electric field generated between two parallel substrate electrodes. ITO substrate electrodes with various patterns are fabricated, ensuring the shape of the formed liquid column matches the pattern. Leveraging the principles of heat transfer, the temperature of the polymer droplet is regulated via a heating stage to enable targeted heating of defined shapes and areas. Experiments delve into the impact of driving parameters on heating time and efficiency, with results affirming the proposed method's capability to govern localized heating for particular regions and configurations accurately.