In space, materials reveal their secrets: COLIS, a new laboratory for studying colloidal gels and glasses in microgravity
Sunscreen that lasts longer, mayonnaise that's more stable, medicine that's more effective: behind these everyday applications lie complex materials (gels and glasses) whose evolution is still poorly understood. To unravel these mechanisms, researchers from the Politecnico di Milano and the Université de Montpellier have designed and developed COLIS, a new laboratory on board the International Space Station, dedicated to the study of flexible materials in microgravity.
An innovative laboratory for observing matter outside the influence of gravity
Gels and glasses, ubiquitous materials in the pharmaceutical, cosmetics and food industries, evolve slowly over time. On Earth, gravity has a subtle but profound influence on these internal dynamics. By placing these materials in space, scientists can finally isolate and analyze these effects.
The fruit of a long-standing collaboration between Luca Cipelletti, a physicist at the Charles Coulomb Laboratory (Université de Montpellier - CNRS), and Roberto Piazza, a professor at the Politecnico di Milano, COLIS (Colloids in Space) represents a major step forward in the eponymous program led by the European Space Agency (ESA), with the support of 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-assembled materials."
Transported to the ISS aboard NASA's Cygnus NG-21 cargo ship and built 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 to understand materials stability
COLIS is based on several major innovations:
- Optical dynamic correlation techniques, exploiting speckle patterns to track the internal restructuring of materials,
- Controlled thermal stimulation to trigger and observe aging processes,
- Measurement of sample turbidity and very rapid fluctuations in the light scattered by the sample, enabling early detection of the formation of crystalline phases.
This latest technology will be used by the teams of Dominique Maes and James Lutsko (Vrije Universiteit Brussel) to study protein crystallization in weightlessness, a decisive step in improving drug stability and optimizing biotechnological processes.
For Luca Cipelletti, " COLIS is the culmination of over twenty-five years of collaboration with the Politecnico di Milano. Bringing the physics of soft materials to the ISS represents a scientific and technological challenge that opens up new perspectives in the study of disordered matter ".
Initial results: the influence of gravity stronger than expected
Initial work by teams from Montpellier and Milan (Luca Cipelletti, Roberto Piazza, Stefano Buzzaccaro and Alessandro Martinelli) shows that gravity influences the structure and properties of flexible materials far more than previously thought. Its effects persist over time, modifying their behavior even in the long term.
" It ' s amazing to see how a force as familiar as gravity silently shapes the materials we use every day. These observations enable us to improve their stability and, ultimately, the quality of life on Earth ", concludes Roberto Piazza.