Patent ID: 8763633

Claim:
A valve for controlling the flow of fluid, said valve comprising: a first plate having apertures extending generally perpendicular through said first plate; a second plate having first apertures extending generally perpendicular through said second plate, the first apertures being substantially offset from the apertures of said first plate; wherein the apertures in the first and second plates are less than 500 μm in diameter; a spacer disposed between said first plate and said second plate to form a cavity therebetween in fluid communication with the apertures of said first plate and the first apertures of said second plate; and, a flap disposed and moveable between said first plate and said second plate, said flap having apertures substantially offset from the apertures of said first plate and substantially aligned with the first apertures of said second plate; whereby said flap is motivated between said first and second plates in response to a change in direction of the differential pressure of the fluid across said valve; and wherein the flap thickness (δ flap ) satisfies the following: δ flap < P 2 ⁢ ⁢ d gap ⁢ 1 16 ⁢ ⁢ f 2 ⁢ 1 ρ flap where P is the amplitude of the oscillating pressure wave, d gap is the flap gap, f is the frequency of the applied pressure differential oscillation and ρ flap is the density of the flap material.