Excitability and traveling waves in renewable active matter

Area of Science:

• Biophysics
• Materials Science
• Cell Biology

Background:

• Living matter possesses unique features of activity and renewability.
• The cell cytoskeleton, with actin and myosin, exemplifies renewable active matter, generating forces and sensing stress.
• Nonreciprocity in living matter leads to unusual mechanical properties like segregation and force chains.

Purpose of the Study:

• To investigate the mechanical excitability arising from the interplay of activity and turnover in renewable active matter.
• To systematically study the dynamics of traveling pulses, including nucleation, movement, and shape.
• To analyze the emergence of spatiotemporal chaos in such systems.

Main Methods:

• Theoretical modeling of renewable active matter.
• Boundary layer analysis to identify homoclinic orbits.
• Numerical analysis of governing partial differential equations.

Main Results:

• The interplay between activity and turnover generates mechanical excitability, observed as traveling waves and pulses.
• A detailed study characterized the nucleation, movement, and shape of traveling pulses.
• Analytical and numerical methods confirmed the existence of homoclinic orbits and spatiotemporal chaos.

Conclusions:

• Renewable active matter exhibits mechanical excitability, including traveling waves, pulses, and chaos, driven by activity and turnover.
• The findings provide a framework for understanding the complex mechanical behaviors of living materials.
• This research has implications for cellular mechanics in various biological contexts, from single cells to tissues.