Patent ID: 8668474

Claim:
An electro-active, valveless pump fitted to or integral with an inlet portion and an outlet portion of a conduit, wherein the pump is located between the inlet and outlet portions, the pump comprising: (a) a pumping chamber comprising at least one pumping chamber wall and having a straight channel which joins two openings of equal size, each of said two openings being at a respective end of the channel, wherein the inlet portion of the conduit is coupled to one opening of said two openings and the outlet portion is coupled to the other opening of said two openings, and wherein the pumping chamber comprises a uniform cross-section in a flow direction from the inlet portion to the outlet portion; (b) a single through hole in the at least one pumping chamber wall; and (c) a fluidless electro-active actuator comprising a membrane covering the single through hole for inducing fluid flow according to the Liebau effect, the electro-active actuator forming part of the pumping chamber wall against which fluid in the conduit flows, wherein the single through hole is arranged in the pumping chamber wall in a manner such that the single through hole is located off-center when viewed in an oscillation direction of the actuator relative to a length of the channel from one of said two openings to the other of said two openings in the pumping chamber, wherein the inlet and outlet portions of the conduit are of equal length and each presents a same impedance to the pumping chamber, and wherein the inlet portion has a first axis of symmetry and the outlet portion has a second axis of symmetry and the first and second axes of symmetry are co-axial.