  In this article, we report experimental and semi analytical findings to
elucidate the electrohydrodynamics EHD of a dielectric liquid droplet impact on
superhydrophobic SH and hydrophilic surfaces. A wide range of Weber numbers We
and electro-capillary numbers Cae is covered to explore the various regimes of
droplet impact EHD. We show that for a fixed We 60, droplet rebound on SH
surface is suppressed with increase of electric field intensity. At high Cae,
instead of the usual uniform radial contraction, the droplets retract faster in
orthogonal direction to the electric field and spread along the direction of
the electric field. This prevents the accumulation of sufficient kinetic energy
to achieve the droplet rebound phenomena. For certain values of We and
Ohnesorge number Oh, droplets exhibit somersault like motion during rebound.
Subsequently we propose a semi analytical model to explain the field induced
rebound phenomenon on SH surfaces. Above a critical Cae 4.0, EHD instability
causes fingering pattern via evolution of spire at the rim. Further, the
spreading EHD on both hydrophilic and SH surfaces are discussed. On both
wettability surfaces and for a fixed We, the spreading factor shows an
increasing trend with increase in Cae. We have formulated an analytical model
based on energy conservation to predict the maximum spreading diameter. The
model predictions hold reasonably good agreement with the experimental
observations. Finally, a phase map was developed to explain the post impact
droplet dynamics on SH surfaces for a wide range of We and Cae.
