A team of scientists from the University of Notre Dame is sending a physical science experiment to the International Space Station (ISS) to better understand bubble dynamics on nanostructured surfaces. Results could lead to improved medical diagnostics and potential new methods for water purification. The investigation, sponsored by the ISS National Laboratory, is launching on Northrup Grumman’s upcoming 17th Commercial Resupply Services (CRS) mission.
For the experiment, the research team will heat metal substrates with nanostructured patterns submerged in liquid to study the resulting bubble dynamics. The team will observe how the bubbles form, grow, and detach from solid surfaces with different nanoscale features. The project, supported by ISS National Lab Commercial Service Provider Space Tango, will use an optical imaging system to record the bubble behavior in near real-time. The microgravity environment of the ISS allows the research team to study thermal bubbles in ways not possible on Earth because of the influence of gravity on fluid physics.
“When gravity-driven buoyancy is removed, we can more clearly study how the surface tension and capillary forces compete with each other,” said Tengfei Luo, principal investigator for the project and professor in the Department of Aerospace and Mechanical Engineering at the University of Notre Dame.
Surface tension affects bubble size and drives the bubble to form a complete sphere, and the capillary force affects the adherence of the bubble to a surface. Understanding the relationship between these two forces and the role they play in thermal bubble formation could have valuable applications.
Thermal bubbles have proven to be a useful method to concentrate biological molecules in liquid samples. Using this method on laboratory samples from patients can allow scientists to detect molecular markers of disease circulating in the blood even at very low concentrations.
“In a laboratory sample, the longer a bubble stays intact and the larger it grows, the more potential biomarkers it can collect,” Luo said.
To optimize bubble dynamics, Luo and his team will examine how different nanostructured surfaces affect bubble development. Knowledge gained from this experiment could increase sensitivity and improve early detection methods for life-threatening diseases such as cancer.
Additionally, results from this investigation could aid in the development of other important applications. For example, thermal bubbles could be used to capture, concentrate, and remove contaminants from water, which has important applications in water purification.
Northrop Grumman CRS-17 is targeted for launch from Wallops Flight Facility no earlier than February 19 at 12:39 p.m. EST. This mission will include more than 15 ISS National Lab-sponsored payloads. To learn more about all ISS National Lab-sponsored research on Northrop Grumman CRS-17, please visit our mission overview page.
# # #
About the International Space Station (ISS) National Laboratory: The International Space Station (ISS) is a one-of-a-kind laboratory that enables research and technology development not possible on Earth. As a public service enterprise, the ISS National Lab allows researchers to leverage this multiuser facility to improve life on Earth, mature space-based business models, advance science literacy in the future workforce, and expand a sustainable and scalable market in low Earth orbit. Through this orbiting national laboratory, research resources on the ISS are available to support non-NASA science, technology and education initiatives from U.S. government agencies, academic institutions, and the private sector. The Center for the Advancement of Science in Space, Inc. (CASIS) manages the ISS National Lab, under Cooperative Agreement with NASA, facilitating access to its permanent microgravity research environment, a powerful vantage point in low Earth orbit, and the extreme and varied conditions of space. To learn more about the ISS National Lab, visit www.ISSNationalLab.org.
