Trapping airborne particles by jumping-droplet condensation on superhydrophobic surface
Inhalation of microscale particles can cause severe health issues in respiratory and cardiovascular systems of humans. Trapping airborne particles by water droplets is one of the most widely used methods to reduce the particle concentration in polluted air. However, generating intensive micro-droplets via spraying or ultrasonic atomization normally requires specialized equipment and a large amount of energy. In this project, I propose a novel and cost-effective approach to capture particles by utilizing abundant self-jumping droplets generated during condensation on a superhydrophobic surface. Since the condensation process is ubiquitous and can be found in various heat transfer devices such as air conditioners, the proposed strategy will significantly reduce the expenses and energy costs for particle removal. In particular, to enhance the particle trapping rate, I intend to explore the rational superhydrophobic surface topography that allows continuous jumping-droplet condensation. I will first analyze the condensing droplet wetting dynamics using the cutting-edge confocal microscopy developed by the host lab. The results obtained will help to optimize the surface structures to achieve the durable condensate repellency. Next, I will investigate the effects of jumping droplet characteristics on the particle-droplet interaction from a single-droplet perspective. Finally, I will use my expertise in thermal physics to quantitatively correlate global condensation heat transfer and particle trapping performance. By integrating these interdisciplinary studies, the project will make a conceptual breakthrough in mitigating air pollution without additional energy consumption, and pave the way for the next-generation climate control devices with built-in air purification capabilities.