Chromatic percolation in two-dimensional multitype particle systems with extended-range homotypic repulsion

Area of Science:

• Physics
• Materials Science
• Biophysics

Background:

• Cells in tissues often repel similar neighbors over long distances.
• Standard jamming models do not account for this diversity.
• Understanding jamming in diverse systems is crucial for tissue mechanics and material design.

Purpose of the Study:

• Introduce and define chromatic percolation for multitype particle systems.
• Map the relationship between chromatic percolation and mechanical jamming.
• Investigate the effect of particle diversity on jamming transitions.

Main Methods:

• Large-scale two-dimensional simulations.
• Varying the number of particle types and packing fraction.
• Charting phase diagrams with mechanical jamming (J-line) and homotypic percolation (P-line).

Main Results:

• Jamming threshold increases with diversity, approaching an achromatic limit.
• More diverse systems pack more densely before becoming rigid.
• Critical jamming behavior remains universal across diversity, dictated by interaction potential.
• At high packing fractions, homotypic percolation separates from mechanical jamming.

Conclusions:

• Particle diversity tunes the onset of rigidity but not the universality of jamming.
• Chromatic percolation provides a framework for understanding jamming in diverse systems.
• Results offer predictions for biological tissues and programmable colloids, guiding material design.