  Accurate and integrable control of different flows within microfluidic
channels is crucial to further development of lab-on-a-chip and fully
integrated adaptable structures. Here we introduce a flexible microactuator
that buckles at a high deformation rate and alters the downstream fluid flow.
The microactuator consists of a confined, thin, dielectric film that buckles
into the microfluidic channel when exposed to voltage supplied through
conductive fluid electrodes. We estimate the critical buckling voltage, and
characterize the buckled shape of the actuator. Finally, we investigate the
effects of frequency, flow rate, and the pressure differences on the behavior
of the buckling structure and the resulting fluid flow. These results
demonstrate that the voltage--induced buckling of embedded microstructures
using fluid electrodes provides a means for high speed attenuation of
microfluidic flow.
