Mechanochemical topological defects in an active nematic

Area of Science:

• Soft Matter Physics
• Chemical Systems Biology
• Materials Science

Background:

• Active nematics exhibit complex topological structures.
• Sensing and responding to topological defects is crucial for biological processes and material design.
• Current methods for defect detection can be complex and limited.

Purpose of the Study:

• To develop a reaction-diffusion system for converting topological information of active nematics into chemical signals.
• To demonstrate a method for dynamically sensing topological defects.
• To explore potential applications in biological systems and bio-inspired materials.

Main Methods:

• Proposed a reaction-diffusion system described by partial differential equations.
• Introduced a curvature-activated reaction dipole term.
• Simulated the system's response to topological defects in passive and active nematics.

Main Results:

• The system successfully generates a concentration field with local extrema at topological defects (±1/2 defects).
• A curvature-activated reaction dipole is sufficient for dynamic topology sensing.
• The system can identify defects in both passive and active nematic systems.

Conclusions:

• A simple feedback system can generate chemical signals in response to nonlocal structures in anisotropic media.
• This approach offers a pathway for generating testable hypotheses in biological morphogenesis.
• Motivates the design of bio-inspired materials with coupled nematic structure and biochemistry.