Systems and methods for ion mobility control
The invention provides, in various embodiments, systems and methods relating to controlling ion behavior in an ion-based analysis system.
1. A method for controlling ion behavior in an ion mobility based analyzer comprising:
providing a flow path for a flow of ions,
generating an ion filter field in the flow path for filtering the flow of ions,
separating ions in the flow of ions according to species, the separating being based on ion-mobility-based behavior of the ions in the ion filter field,
applying an influencing electric field to a portion of the flow path to control the behavior of ions in the flow of ions.
2. The method of claim 1 comprising providing first and second pairs of control electrodes for generating at least a portion of the filter field, each pair of control electrodes including first and second control electrodes facing each other across a portion of the flow path.
3. The method of claim 2 comprising providing a resistive material extending along a portion of the flow path between the first control electrode of the first pair of control electrodes and the first control electrode of the second pair of control electrodes.
4. The method of claim 3 comprising generating the influencing electric field by applying a difference in voltage potential between the first and second pair of control electrodes.
5. The method of claim 4 comprising forming an array of control electrode pairs along the flow path.
6. The method of claim 4 wherein the influencing field at least partially propels ions through the ion filter field.
7. The method of claim 6 comprising propelling ions of one of a positive and negative polarity through the ion filter field.
8. The method of claim 6 comprising applying a potential to a steering electrode proximate to an end of the ion filter field to generate an ion steering electric field.
9. The method of claim 8 comprising positioning the steering electrode outside of the ion filter field.
10. The method of 4 comprising forming at portion of the mobility based analyzer in a chip assembly.
11. The method of claim 10 comprising interfacing the chip assembly with a gas chromatograph.
12. The method of claim 1 comprising inhibiting one or more filter signals from interfering with a detector signal using at least one guard electrode.
13. The method of claim 3 wherein the resistive material includes semiconductor material.
14. The method of claim 3 comprising supporting at least one of the control electrodes using the resistive material.
15. The method of claim 14 comprising forming at least one of the control electrodes on a portion of the resistive material.
16. The method of claim 15 wherein the forming includes a metallization technique.
17. The method of claim 1 comprising generating the filter field and applying the influencing electric field at least partially via a control electrode, wherein the influencing field propels a portion of the ions through the ion filter field and wherein a portion of the flow path is in communication with a resistive semiconductor material.
18. The method of claim 17 comprising dissipating a portion of a charge in the flow path via the control electrode.