Spontaneous division and motility in active nematic droplets

Area of Science:

• Soft Matter Physics
• Active Matter Systems
• Hydrodynamics

Background:

• Active droplets are model systems for studying self-organization and emergent behaviors.
• Nematic order introduces complex internal structures and dynamics.
• Understanding active stresses and their interplay with fluid mechanics is crucial.

Purpose of the Study:

• To investigate the mechanical properties of active droplets with internal nematic order.
• To explore the emergence of cell-like functions such as motility and division.
• To identify physical parameters controlling these behaviors.

Main Methods:

• Numerical simulations of active droplet hydrodynamics.
• Modeling of active stresses arising from nematic order.
• Analysis of the nematic director field and its defects.
• Parametric study of the active capillary number.

Main Results:

• Demonstration of spontaneous motility driven by self-generated hydrodynamic flows.
• Observation of spontaneous droplet division linked to internal nematic defects.
• Identification of the active capillary number as a key parameter to control motility and division.
• Correlation between active stresses, nematic director defects, and emergent behaviors.

Conclusions:

• Active droplets with internal nematic order can mimic fundamental functions of living cells.
• Hydrodynamic flows generated by active stresses and nematic defects drive motility and division.
• Selective control over these cell-like behaviors is achievable by tuning the active capillary number.