  Generation of mechanical force regulated by external electric field is
studied both theoretically and by molecular dynamics (MD) simulations. The
force arises in deformable bodies linked to the free end of a grafted
polyelectrolyte chain which is exposed to electric field that favours its
adsorption. We consider a few target bodies with different force-deformation
relations including (i) linear and (ii) cubic dependences as well as (iii)
Hertzian-like force. Such force-deformation relations mimic the behaviour of
(i) coiled and (ii) stretched polymer chains, respectively, or (iii) that of a
squeezed colloidal particle. The magnitude of the arising force varies over a
wide interval although the electric field alters within a relatively narrow
range only. The predictions of our theory agree quantitatively well with the
results of numerical simulations. Both cases of zero and finite electrical
current are investigated and we do not obtain substantial differences in the
force generated. The phenomenon studied could possibly be utilised to design,
e.g., vice-like devices to fix nano-sized objects.
