  We search for detectable signatures of f(R) gravity and its chameleon
screening mechanism in the baryonic and dark matter (DM) properties of
simulated void galaxies. The enhancement of the gravitational acceleration can
have a meaningful impact on the scaling relations as well as on the halo
morphology. The galaxy rotational velocity field (calculated with the velocity
of the gas disc and the acceleration fields) deviates from the typical values
of the Tully-Fisher Relation (TFR) in GR. For a given stellar mass, f(R)
gravity tends to produce greater maximum velocities. On the other hand, the
mass in haloes in f(R) gravity is more concentrated than their counterparts in
GR. This trend changes when the concentration is calculated with the dynamical
density profile, which takes into account the unscreened outer regions of the
halo. Stellar discs interact with the overall potential well in the central
regions, modifying the morphology of the screening regions and reshaping them.
We find a trend for galaxies with a more dominant stellar disc to deviate
further from round screening regions. We find that small haloes are less
triaxial and more round in f(R) than their GR counterparts. The difference
between halo morphology becomes smaller in f(R) haloes whose inner regions are
screened. These results suggest possible observables that could unveil modified
gravity effects on galaxies in voids in future cosmological tests of gravity.
