A valveless micropump includes a hollow pump chamber having a driving element
coupled
thereto, an inlet channel coupled to the hollow pump chamber, and an outlet channel
coupled to the hollow pump chamber. The inlet channel, the hollow pump chamber,
and the outlet channel define a fluid flow path through the inlet channel, the
hollow pump chamber, and the outlet channel. At least one direction-sensitive element
disposed in the flow path within one of the inlet and outlet channels and comprising
a direction-sensitive element, is installed at an angle which produces a drag ratio
greater than unity on fluid in the flow path. The driving element may comprise
an electrostatic/piezoelectric member. Various embodiments of the valveless pump
include one or more of the airfoil elements mounted in one, the other or both of
the inlet and outlet channels, including embodiments in which one or more cascades
of the airfoil elements are mounted in the inlet channel and the outlet channel.
