Micromachined field asymmetric ion mobility filter and detection system
A micromechanical field asymmetric ion mobility filter for a detection system includes a pair of spaced substrates defining between them a flow path between a sample inlet and an outlet; an ion filter disposed in the path and including a pair of spaced filter electrodes, one electrode associated with each substrate; and an electrical controller for applying a bias voltage and an asymmetric periodic voltage across the ion filter electrodes for controlling the paths of ions through the filter.
1 . (canceled)
2 . A field asymmetric ion mobility filter for a detection system comprising:
a housing including a flow path between a sample inlet and an outlet,
a micromechanical ion mobility based filter disposed in the flow path and including a pair of spaced filter electrodes, at least one filter electrode being formed on a substrate, and
an electrical controller for applying a bias voltage and an asymmetric periodic voltage across the ion filter electrodes for controlling the paths of ions while the ions are flowing through the ion mobility based filter.
3 . The system of claim 2 comprising a detector for detecting ions exiting the filter and generating an ion detection current.
4 . The system of claim 3 , wherein the detector includes at least one detector electrode.
5 . The system of claim 4 , wherein the at least one detector electrode is formed on a substrate.
6 . The system of claim 2 comprising a spacer for separating the filter electrodes.
7 . The system of claim 6 , wherein the spacer includes silicon.
8 . The system of claim 7 , wherein the spacer is formed from at least one of dicing and etching.
9 . The system of claim 6 , wherein the spacer defines the distance between the filter electrodes.
10 . The system of claim 2 comprising a heater within the flow path.
11 . The system of claim 2 comprising a pump in communications with the flow path for supporting, at least in part, the flow of ions along the flow path.
12 . A method of filtering ions comprising:
providing a housing including a flow path between a sample inlet and an outlet,
disposing a micromechanical ion mobility based filter in the flow path, the filter including a pair of spaced filter electrodes, at least one filter electrode being formed on a substrate, and
applying a bias voltage and an asymmetric periodic voltage across the ion filter electrodes for controlling the paths of ions while the ions are flowing through the ion mobility based filter.
13 . The method of claim 12 comprising detecting ions exiting the filter and generating an ion detection current.
14 . The method of claim 13 , wherein the detecting is performed by at least one detector electrode.
15 . The method of claim 14 , wherein the at least one detector electrode is formed on a substrate.
16 . The method of claim 12 comprising separating the filter electrodes using a spacer.
17 . The method of claim 16 , wherein the spacer includes silicon.
18 . The method of claim 17 , wherein the spacer is formed from at least one of dicing and etching.
19 . The method of claim 16 comprising defining the distance between the filter electrodes using the spacer.
20 . The method of claim 12 comprising heating a portion of the flow path.
21 . The method of claim 12 comprising interfacing a pump with the flow path for supporting, at least in part, the flow of ions along the flow path.