  We formulate and explore a generic continuum model of a polarizable active
layer with neo-Hookean elasticity and chemo-mechanical interactions.
Homogeneous solutions of the model equations exhibit a stationary long-wave
instability when the medium is activated by expansion, and an oscillatory
short-wave instability in the case of compressive activation. Both regimes are
investigated analytically and numerically. The long-wave instability initiates
a coarsening process, which provides a possible mechanism for the establishment
of permanent polarization in spherical geometry.
