Clusters, asters, and collective oscillations in chemotactic colloids.

Area of Science:

• Biomimetics and active matter physics
• Theoretical description of synthetic life-like systems

Background:

• Creating synthetic systems that mimic life's properties (motility, gradient-sensing) is a major challenge.
• Active components transforming chemical energy into motion are key to artificial motility.
• Catalytic colloidal swimmers are a promising example of such active systems.

Purpose of the Study:

• To provide a comprehensive theoretical description of gradient-sensing in individual swimmers.
• To develop a framework for studying the collective behavior of these active colloids.
• To explore emergent phenomena and control strategies for synthetic active matter.

Main Methods:

• Theoretical modeling of individual catalytic colloidal swimmer behavior.
• Analysis of gradient-sensing leading to chemotaxis or anti-chemotaxis.
• Framework development for studying collective dynamics and emergent phenomena.

Main Results:

• Demonstrated controllable gradient-sensing for individual swimmers.
• Identified condensation of positional and orientational degrees of freedom, forming clusters and asters.
• Observed analogs to gravitational collapse, plasma oscillations, and electrostatic screening in the long-ranged limit.

Conclusions:

• The theoretical framework allows for predictable control over swimmer behavior and collective dynamics.
• Catalysis kinetics and surface properties can be tuned to achieve diverse emergent behaviors.
• This work advances the engineering of emergent behavior in synthetic active matter.