Transforming gels through training – TrainGel

Wider Research Context / Theoretical Framework:
Mechanical and thermal conditioning processes have been used for centuries by the humankind to produce materials with the desired properties. Of particular interest is the application of this ideas to amorphous materials, such as glasses. Amorphous materials demonstrate unique responses to energy inputs, exhibiting phenomena such as aging and overaging. The study of these materials, particularly under mechanical training, reveals complex behaviors tied to their energy landscape. Recent advancements have expanded our understanding of mechanical memory in these materials, showing how they adapt and encode histories of mechanical interactions.

Hypotheses/Research Questions/Objectives:
This project aims to extend the concept of training from glasses to gels, a relatively underexplored area so far. We hypothesize that colloidal and macromolecular gels will exhibit unique responses to training, potentially leading to novel structural and mechanical properties, such as increased strength, reduced elasticity, or induced anisotropy.

Approach/Methods:
Combining experimental techniques like dynamic light scattering, particle tracking, differential dynamics microscopy, rheology, and microrheology the project will investigate the effects of various training regimens on colloidal and macromolecular gels. This approach includes exploring temperature-sensitive colloidal interactions, mechanical shear forces, and high-power ultrasound, providing a comprehensive understanding of how training influences gel properties. At the same time, we will conduct advanced simulations to examine and analyze the structure and dynamics of the gels under various training conditions.

Level of Originality / Innovation:
Focusing on gels marks a significant departure from the more commonly studied glasses, representing an innovative shift in soft matter physics. The project's novel approach aims to uncover new mechanisms of mechanical memory and adaptability in gel materials.

Primary Researchers Involved:
The team merges two national clusters of scientists with extensive experience in studying out-of-equilibrium soft matter, including gels in particular. The French node is coordinated by Thomas Gibaud (ENS Lyon) and includes Stefano Aime (ESPCI Paris), and Frederic Pignon (CNRS Grenoble). The Austrian node is coordinated by Roberto Cerbino, and includes Christos Likos, both at the University of Vienna. Overall, the team composition covers all the aspects relevant to the project, mastering a wide portfolio of experimental, theoretical and numerical techniques, and bringing demonstrated expertise on an extended class of gels, including biocompatible gels for cell biology applications.