  The challenge of inducing and controlling localized fluid flows for generic
force actuation and for achieving efficient mass transport in microfluidics is
key to the development of next generation miniaturized systems for chemistry
and life sciences. Here we demonstrate a methodology for the robust generation
and precise quantification of extremely strong flow transients driven by vapor
bubble nucleation on spatially isolated plasmonic nanoantennas excited by
light. The system is capable of producing peak flow speeds of the order mm/s at
modulation rates up to 100 Hz in water, thus allowing for a variety of
high-throughput applications. Analysis of flow dynamics and fluid viscosity
dependence indicate that the transient originates in the rapid bubble expansion
that follows nucleation rather than being strictly thermocapillary in nature.
