  Low power actuation of sessile droplets is of primary interest for portable
or hybrid lab-on-a-chip and harmless manipulation of biofluids. In this paper,
we show that the acoustic power required to move or deform droplets via surface
acoustic waves can be substantially reduced through the forcing of the drops
inertio-capillary modes of vibrations. Indeed, harmonic, superharmonic and
subharmonic (parametric) excitation of these modes are observed when the high
frequency acoustic signal (19.5 MHz) is modulated around Rayleigh-Lamb
inertio-capillary frequencies. This resonant behavior results in larger
oscillations and quicker motion of the drops than in the non-modulated case.
