In space, materials reveal their secrets: COLIS, a new laboratory for studying colloidal gels and glasses in microgravity
Sunscreen that lasts longer, more stable mayonnaise, more effective medication: behind these everyday applications lie complex materials (gels and glasses) whose behavior is still poorly understood. To unravel these mechanisms, researchers from the Politecnico di Milano and the University of Montpellier have designed and developed COLIS, a new on-board laboratory on the International Space Station dedicated to the study of soft materials in microgravity.
An innovative laboratory for observing matter outside the influence of gravity
Gels and glasses—materials that are ubiquitous in the pharmaceutical, cosmetics, and food industries—change slowly over time. On Earth, gravity subtly yet profoundly influences this internal dynamic. By placing these materials in space, scientists can finally isolate and analyze these effects.
The result of a long-standing collaboration between Luca Cipelletti, a physicist at the Charles Coulomb Laboratory (University of Montpellier – CNRS), and Roberto Piazza, a professor at the Politecnico di Milano, COLIS (Colloids in Space) represents a major advance in the eponymous program led by the European Space Agency (ESA), with support from ASI and CNES.
“Studying these materials in microgravity allows us to isolate the effect of gravity, a silent but decisive force,” explains Roberto Piazza. “This understanding is essential for designing more stable formulations, from controlled-release drugs to self-assembling materials.”
Transported to the ISS aboard NASA’s Cygnus NG-21 cargo spacecraft and developed by Redwire Space, COLIS is now fully operational. It analyzes samples of colloidal gels and glasses containing nanoparticles, focusing on the aging processes within them.
Cutting-edge technologies for understanding material stability
COLIS is based on several major innovations:
- Dynamic optical correlation techniques that use speckle patterns to track the internal restructuring of materials,
- Controlled thermal stimuli that trigger and allow for the observation of aging processes,
- Measuring the turbidity of samples and the very rapid fluctuations in the light scattered by the sample, which can provide early detection of the formation of crystalline phases.
This latest technology will be used by the teams led by Dominique Maes and James Lutsko (Vrije Universiteit Brussel) to study protein crystallization in microgravity, a crucial step in improving the stability of drugs and optimizing biotechnological processes.
According to Luca Cipelletti, “COLIS is the culmination of more than twenty-five years of collaboration with the Politecnico di Milano. Bringing the physics of soft matter to the ISS represents a scientific and technological challenge that opens up new perspectives in the study of disordered matter.”
Initial results: Gravity’s influence is stronger than expected
Initial research conducted by teams in Montpellier and Milan (Luca Cipelletti, Roberto Piazza, Stefano Buzzaccaro, and Alessandro Martinelli) shows that gravity influences the structure and properties of soft materials far more than previously thought. Its effects persist over time, altering their behavior even in the long term.
“It’s surprising to see just how much a force as familiar as gravity silently shapes the materials we use every day. These observations allow us to improve their stability and, ultimately, the quality of life on Earth,” concludes Roberto Piazza.