Dynamic density functional study of chemomechanical feedback-controlled microgel colloids

• Applicant: Professor Dr. Joachim Dzubiella
• Subject Area: Statistical Physics, Nonlinear Dynamics, Complex Systems, Soft and Fluid Matter, Biological Physics
• Term: since 2026
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 575626147

Recent experiments demonstrate a fine control of catalyzed chemical reactions compartmentalized in responsive hydrogel-based colloids. The size-responsiveness of these catalytically active colloids to own and environmental chemical stimuli, such as pH changes, allows the implementation of mechanochemical feedback cycles with drastic consequences on their many-body structure, dynamics, and response in liquid colloidal dispersions. Understanding and controlling the novel, multifarious collective behavior of these emerging active colloids will lead to significant advancements in the design of artificial cells and novel active and soft functional materials with life-like properties, such as autonomy and adaptivity. However, the control of the larger scale nonequilibrium dynamics is hampered by the large physicochemical parameter space and the sensitivity of emergent phases to intrinsic chemical and conformational relaxation times. Here, we aim to develop a comprehensive theory based on time-dependent dynamic density functional theory (DDFT) for the joint probability density distribution of the colloidal positions and sizes coupled to the diffusive dynamics of the chemical product (e.g., pH) and fuel fields. The theory will be employed to uncover various collective states and how they are controlled by the input parameters. External fields can be naturally included in DDFT and will be used to study the nonequilibrium response behavior and how to control the transitions between dynamical states. The output will guide and interpret contemporary experiments of our collaboration partners, in particular, with applications in homeostasis (self-regulation) and adaptivity of liquid dispersions of the feedback-controlled active colloids.

• DFG Programme: Research Grants
• International Connection: Spain
• Co-Investigators: Professor Dr. Sören Bartels; Professor Dr. Andreas Walther
• Cooperation Partner: Professor Dr. Arturo Moncho Jordá