2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/95661Mechanically active cells in soft media act as force dipoles. The resulting elastic interactions are long-ranged and favor the formation of strings. We show analytically that due to screening, the effective interaction between strings decays exponentially, with a decay length determined only by geometry. Both for disordered and ordered arrangements of cells, we predict novel phase transitions from paraelastic to ferroelastic and anti-ferroelastic phases as a function of Poisson ratio.4 pages, Revtex, 4 Postscript figures includedSoft Condensed MatterMaterials ScienceCell Behaviortext