Patent ID: 8231707

Claim:
An apparatus for separating a chosen gas species contained in a gas mixture, which comprises in combination: a cylindrical piezoelectric transducer defining an interior cavity having a surface defining an axis, wherein the interior cavity has an acoustic resonance that is matched to a breathing-mode acoustic resonance of the cylindrical piezoelectric transducer when the interior cavity is filled with the gas mixture; a function generator connected to apply periodic electrical excitation to the cylindrical piezoelectric transducer such that resonant acoustic waves having successive one-half periods of acoustic compression and successive one-half periods of acoustic rarefaction are generated in the interior cavity and form regions of concentrated acoustic force, wherein the interior cavity surface is reshaped from a circular cross-section such that the regions of concentrated acoustic force are axial regions parallel to the axis of the interior cavity surface; input means for introducing the gas mixture containing the chosen species into the vicinity of the regions of concentrated acoustic force formed by the resonant acoustic waves such that the chosen gas species move through the regions of concentrated acoustic force and are concentrated therein; a source of light having a selected wavelength absorbed by the chosen gas species, the light therefrom being directed parallel to the axis; and means for pulsing on said source of light during selected intervals within the successive one-half periods of acoustic compression and off during selected intervals within the successive one-half periods of acoustic rarefaction, or pulsing on said source of light during selected intervals within the successive one-half periods of acoustic rarefaction and off during selected intervals within the successive one-half periods of acoustic compression, wherein light-induced drift is generated in the absorbing chosen gas species.