Understanding the dynamics of surface bubble formation and growth on heated surfaces holds significant implications for diverse modern technologies. While such investigations are traditionally confined to terrestrial conditions, the expansion of space exploration and economy necessitates insights into thermal bubble phenomena in microgravity. In this work, we conduct experiments in the International Space Station to study surface bubble nucleation and growth in a microgravity environment and compare the results to those on Earth. Our findings reveal significantly accelerated bubble nucleation and growth rates, outpacing the terrestrial rates by up to ~30 times. Our thermofluidic simulations confirm the role of gravity-induced thermal convective flow, which dissipates heat from the substrate surface and thus influences bubble nucleation. In microgravity, the influence of thermal convective flow diminishes, resulting in localized heat at the substrate surface, which leads to faster temperature rise. This unique condition enables quicker bubble nucleation and growth. Moreover, we highlight the influence of surface microstructure geometries on bubble nucleation. Acting as heat-transfer fins, the geometries of the microstructures influence heat transfer from the substrate to the water. Finer microstructures, which have larger specific surface areas, enhance surface-to-liquid heat transfer and thus reduce the rate of surface temperature rise, leading to slower bubble nucleation. Our experimental and simulation results provide insights into thermal bubble dynamics in microgravity, which may help design thermal management solutions and develop bubble-based sensing technologies.

了解表面气泡在加热表面形成和生长的动态对于各种现代技术具有重要意义。虽然此类研究传统上仅限于陆地条件，但太空探索和经济的扩展需要深入了解微重力下的热气泡现象。在这项工作中，我们在国际空间站进行实验，研究微重力环境中表面气泡的成核和生长，并将结果与​​地球上的结果进行比较。我们的研究结果表明，气泡成核和生长速度显着加快，比陆地速度快约 30 倍。我们的热流体模拟证实了重力引起的热对流的作用，它从基板表面散发热量，从而影响气泡成核。在微重力下，热对流的影响减弱，导致基板表面局部发热，从而导致温度上升更快。这种独特的条件使气泡能够更快地成核和生长。此外，我们强调了表面微观结构几何形状对气泡成核的影响。作为传热翅片，微观结构的几何形状影响从基材到水的热传递。更精细的微观结构具有更大的比表面积，可以增强表面与液体的传热，从而降低表面温度上升的速度，从而减慢气泡成核速度。我们的实验和模拟结果提供了对微重力下热气泡动力学的见解，这可能有助于设计热管理解决方案和开发基于气泡的传感技术。