Dr. Hassan Masoud, Associate Professor of Mechanical Engineering at Clemson University, has been awarded a research grant funded jointly by the National Science Foundation (NSF) and the Center for the Advancement of Science in Space (CASIS), in collaboration with NASA. The grant supports a pioneering project that aims to explore the dynamics of active particles moving along spherical fluidic interfaces in the unique microgravity environment of the International Space Station (ISS).
The research seeks to uncover fundamental insights into a phenomenon known as Marangoni propulsion, where particles move due to variations in surface tension. While this behavior has been studied on flat surfaces, Dr. Masoud’s team will be the first to investigate it on curved interfaces—something that is virtually impossible to achieve on Earth due to gravity and other constraints.
“Conducting these experiments aboard the ISS is essential for understanding how active particles interact and move on spherical fluid interfaces,” said Dr. Masoud. “Microgravity allows us to eliminate the gravitational effects that dominate on Earth, providing a clearer view of the fundamental forces at play.”
Marangoni propulsion can be observed in various natural and engineered systems. For example, certain insects secrete substances that lower surface tension to quickly traverse water surfaces, aiding in rapid escape or movement. In another instance, a simple soap or camphor boat moves across the water as the gradual release of a surfactant creates a surface tension gradient, propelling it forward. This principle is also at work in the movement of bacterial colonies that secrete chemicals to reduce surface tension, enhancing their mobility towards nutrient-rich areas.
The insights gained from this research hold promise for numerous applications, ranging from the design of programmable micro-robots for targeted drug delivery and advanced manufacturing processes to understanding natural systems like the collective movement of bacteria and water-walking insects.
The project, led by Dr. Masoud, is a collaborative effort involving researchers from the University of Massachusetts Amherst and engineers from Zin Technologies Inc., who will help implement the experiments aboard the ISS. The findings could pave the way for innovative technologies that address challenges in fields as diverse as medicine, engineering, and environmental science.