Scientists from the Raman Research Institute (RRI), an autonomous institute of the Department of Science and Technology, have published a study in the Journal of Colloid and Interface Science demonstrating how temperature shocks can momentarily convert jammed systems into liquid states to erase memory imprints. The research team, including Sonali Kawale (first author and PhD student) and Ranjini Bandyopadhyay (co-author), experimented with microgel particles that can absorb 300-500 times their weight in water, materials commonly used in diapers and sanitary napkins.
The study found that by applying sudden temperature ramp rates (thermal shocks), particles rearranged and sent jammed systems into temporary liquid states. This process eliminated asymmetries in structural recovery paths that previously showed different trajectories during heating and cooling cycles to reach the target temperature of 20°C. The research specifically demonstrated that the system's behavior depends not only on initial and final temperatures but also on the path taken during temperature changes.
The findings have significant implications for drug delivery applications where microgel particles are used as temperature-responsive coatings. These particles swell when cool (like puffed-up jelly) to load drugs, then collapse when rising above 34°C (slightly below body temperature) to squeeze out medicine at targeted sites such as tumors. Understanding how external perturbations like thermal shocks influence structural recovery could enhance targeted drug release and reduce side effects. The team plans future work to study how path-dependent dynamics of jammed systems respond to mechanical shocks compared to thermal shocks. Publication reference: 10.1016/j.jcis.2026.139830.