Rich complex behaviour of self-assembled nanoparticles far from equilibrium.

Area of Science:

• Physics and Biology Interface
• Nonliving Systems
• Complex Behavior Emergence

Background:

• Fundamental question on minimum requirements for complex behavior from nonliving systems remains unanswered.
• Understanding emergence in physics and biology is crucial for advancing both fields.

Purpose of the Study:

• To investigate the minimum requirements for the emergence of complex behavior from nonliving systems.
• To report complex behaviors in a simplified colloidal nanoparticle system.

Main Methods:

• Utilized ultrafast laser pulses to create spatiotemporal temperature gradients, driving the system far from equilibrium.
• Induced Marangoni flow to aggregate colloidal nanoparticles, counteracted by Brownian motion.
• Leveraged nonlinear feedback mechanisms between flow, aggregate, and Brownian motion for control.

Main Results:

• Observed complex behaviors analogous to living organisms in colloidal nanoparticle aggregates.
• Demonstrated self-sustainment, self-regulation, self-replication, and self-healing of aggregates within seconds.
• Showcased external control with minimal intervention and coexistence/competition of aggregate patterns.

Conclusions:

• Complex behaviors can emerge from simple, nonliving systems under specific physical conditions.
• The study provides insights into the physical basis of life-like properties.
• Minimal intervention allows for rapid, complex pattern formation and dynamic evolution.