Inclusions


 Flexible passive inclusions can spontaneously curve and move due to unbalanced pressures:

 

yellow ball An asymmetric inclusion will experience a force,

     

and acts as a pump causing a counter-flow current of active particles:

Asymmetric inclusion acts as pump; conservation of current leads to long-range modulations of active particle density

yellow ball Long-range density/current disturbances lead to long-range interactions between inclusions,

and with confining boundaries

Inclusion can be localized to the boundary, or to center of circular container

Y. Ben Dor, Y. Kafri, M. Kardar, J. Tailleur, Phys. Rev. E 106, 044604 (2022)