Patent ID: 7358504

Claim:
An apparatus for separating ions comprising: an electrode stack having a length defined along a stacking direction and comprising a plurality of electrodes, each electrode of the electrode stack being spaced apart from an adjacent electrode of the electrode stack along the stacking direction, each electrode of the electrode stack having an edge defining a portion of an edge of the electrode stack; at least an electrode spaced apart from the edge of the electrode stack in a direction transverse to the stacking direction, the space between the at least an electrode and the edge of the electrode stack defining an analytical gap for allowing ions to propagate therebetween along the stacking direction; an ion outlet plate disposed adjacent to a first end of the electrode stack and spaced-apart from the electrode stack along the stacking direction the ion outlet plate defining an ion outlet for extracting from the analytical gap ions propagating along the stacking direction; and, at least an electrical controller for electrically coupling to at least one of an electrode of the plurality of electrodes of the electrode stack and the at least an electrode, for applying an asymmetric waveform voltage between the electrode of the plurality of electrodes of the electrode stack and the at least an electrode and for applying a direct current voltage between the electrode of the plurality of electrodes of the electrode stack and the at least an electrode so as to establish an electric field within the analytical gap.