Fluid flow can be directed and controlled by a variety
of mechanisms within industrial and biological environments. Advances in
microfluidic technology have required innovative ways to control fluid flow on a
small scale, and the ability to actively control fluid flow within microfluidic devices
is crucial for advancements in nanofluidics, biomedical fluidic devices, and digital
microfluidics. In this work, we present a means for microfluidic control via the electrical
actuation of thin, flexible valves within microfluidic channels. These structures
consist of a dielectric elastomer confined between two compliant electrodes that can
be actively and reversibly buckle out of plane to pump fluids from an applied voltage.
The out-of-plane deformation can be quantified using two parameters: net change
in surface area and the shape of deformation. Change in surface area depends on
the voltage, while the deformation shape, which significantly affects the flow rate, is
a function of voltage, and the pressure and volume of the chambers on each side of
the thin plate. The use of solid electrodes enables a robust and reversible pumping
mechanism that will have will enable advancements in rapid microfluidic diagnostics,
adaptive materials, and artificial muscles.