Light-controlled assembly of active colloidal molecules.

Area of Science:

• Soft Matter Physics
• Active Matter Systems
• Biophysics

Background:

• Active matter exhibits complex self-assembly forbidden in equilibrium systems.
• Controlling active self-assembly typically requires engineering individual motile components.

Purpose of the Study:

• To develop a novel route for controlling active self-assembly.
• To engineer active molecules with emergent dynamic behaviors using external stimuli.

Main Methods:

• Utilized laser light to control the binding of immotile microspheres.
• Combined experimental studies with computational simulations.
• Investigated two-species systems of microspheres.

Main Results:

• Demonstrated emergent activity in assembled structures (active molecules).
• Observed complex behaviors including migration, spinning, and rotation.
• Showcased light-controllable nonreciprocal interactions driving assembly dynamics.

Conclusions:

• Activity can emerge from the collective behavior of immotile units under specific binding conditions.
• Light-based control offers a new paradigm for designing and understanding active materials.
• This approach provides insights into living matter principles and inspires novel active material design.