Micromachined field asymmetric ion mobility filter and detection system

Abstract

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.