  The wetting of solid surfaces can be manoeuvred by altering the energy
balance at the interfacial region. While electric field acts favourably to
spread a droplet on a rigid surface, this tendency may be significantly
suppressed over soft surfaces, considering a part of the interfacial energy
being utilized to deform the solid elastically by capillary forces. Here, we
bring out a unique mechanism by virtue of which addition of nano-particles to
the droplet brings in a favourable recovery of the electro-spreading
characteristics of a soft surface, by realizing an alteration in the effective
dielectric constant of the interfacial region. Our experiments further
demonstrate that this mechanism ceases to be operative beyond a threshold
volume fraction of the particle suspension, due to inevitable contact line
pinning. We also develop a theory to explain our experimental observations. Our
findings provide a non-contact mechanism for meniscus spreading and droplet
control, bearing far-reaching implications in biology and engineering.
