Micromachined field asymmetric ion mobility filter and detection system

A field asymmetric ion mobility system comprising:

• an input part and an output part;
• a pair of insulative substrates defining between them a flow path for the flow of ions;
• a pair of ion filter electrodes disposed opposite each other in the flow path, one electrode associated with each substrate;
• an electronic controller input for applying of an asymmetric periodic voltage to the ion filter electrodes for controlling the path of said ions in the flow path;
• and the asymmetric periodic voltage being compensated for ion mobility to pass a desired species of said ions through said filter;
• the insulative substrates electrically insulating the filter electrodes from the output part;
• and
• ions in the flow path passing from the filter electrodes to the output part under control of the compensated applied asymmetric voltage.

A field asymmetric ion mobility system comprising

• an ion input part and a spectrometer part;
• the spectrometer part having an ion filter part, an isolation part, and an output part, ions being delivered to the ion filter part by the input part;
• the isolation part facilitating non-conductive connection of the filter part and the output part;
• a flow channel extending from the filter part through the isolation part to the output part;
• a controller part, the controller part for applying electrical potentials to the filter part, the electrical potentials including an asymmetric periodic voltage, for generating a control field;
• said spectrometer part further comprising planar substrate surfaces opposite each other and each carrying an opposing electrode, the ion filter part including said opposing electrodes across from each other in the flow channel;
• the flow channel defining a first flow path region for application of the control field to ions in the filter part, the ion filter part being located in the first flow path region;
• the flow channel also defining a second flow path region, the isolation part being located in the second flow path region after the first region and before the output part;
• the ion filter part passing ions in the flow channel under influence of the control field;
• and
• ions that are passed by the filter part traveling through the isolation part to the output part for detection, the isolation part isolating the control field from the output part.

A field asymmetric ion mobility system comprising:

• an input part and a detector part;
• cooperating spaced-apart substrates defining between them a flow path for the flow of ions;
• a plurality of electrodes, including a pair of ion filter electrodes opposite each other and disposed in the flow path between the input part and detector part, one filter electrode associated with each substrate and defining an ion filter in the flow path;
• the input part configured for receiving samples, the samples being ionized and comprised of a variety of ions, the ion filter for filtering the ions in the flow path;
• the filter electrodes for application of an alternating asymmetric periodic voltage for generating a filter field with high and low field conditions, the filter field for controlling the travel of the ions in the filter, the filter field being compensated to pass selected ions through the filter;
• the filter electrodes cooperating with the applied voltage and the flow path for simultaneously passing a selected plurality of the ions in the flow path to the detector part, the plurality of the ions including separate positive and negative ions;
• the detector part enabling simultaneous detection of the separate positive and and negative ions;
• and
• the detector part further configured for providing output information representative of this simultaneous detection.

A field asymmetric ion mobility detection system comprising:

• an input part and an output part,
• at least a pair of spaced insulated substrates cooperating to define between them an enclosed planar flow path for the flow of ions from the input part to the output part;
• a plurality of electrodes opposite each other and defined in the flow path the plurality defining at least one filter electrode associated with each substrate to form an ion filter section;
• and
• an electronics part configured to apply controlling signals to the electrodes, and the electronics part applying an asymmetric periodic signal across the filter electrodes for filtering the flow of ions in the flow path, said filter being compensated to pass desired ion species out of the filter section.

A field asymmetric ion mobility system comprising:

• a spacer extending along a longitudinal axis defining a flow path between a sample inlet and an outlet;
• an ion filter disposed in the flow path and including a pair of spaced filter electrodes spaced apart by said spacer;
• said ion filter further comprising substrate surfaces opposite each other and carrying said spaced filter electrodes;
• and
• an electrical input supplying an asymmetric periodic voltage across the ion filter electrodes for generating a control field, the control field controlling the paths of ions traveling through the filter along the longitudinal axis toward the outlet.

A micromechanical field asymmetric ion mobility filter for a detection system comprising:

• a pair of spaced planar substrates defining between them a flow path between a sample inlet and an outlet;
• an ion filter disposed in the path, further including at least a pair of spaced electrodes, the filter comprising at least one of the electrodes on each substrate opposite each other;
• an electrical controller for applying voltages, including an asymmetric periodic voltage applied to the filter, for controlling the paths of ions through the filter;
• and
• a heater for heating the flow path.

A field asymmetric ion mobility filter system comprising:

• a flow path extending between a sample inlet and an outlet;
• an ion filter disposed in the flow path;
• said ion filter further comprising electrodes opposite each other;
• an electrical controller configured to apply an asymmetric periodic voltage across the ion filter electrodes for controlling the path of ions through the ion filter;
• and
• a selection circuit configured for selectively adjusting the duty cycle of the asymmetric periodic voltage to enable ion species from the sample inlet to be separated, with desired species being passing through the filter for detection.

In an ion mobility filter system having a flow path that defines an ion inlet, an output, and an ion filter with opposed electrodes in the flow path between the inlet and the output, the filter passing ions flowing from the inlet to the output, a method for filtering ions, the method comprising the steps of:

• applying an asymmetric periodic voltage to the ion filter for generating a filter field for controlling the path of ions in the filter between the electrodes,
• providing the field with high and low field conditions,
• adjusting the duty cycle of the asymmetric periodic voltage to enable ion species to be separated by the filter according to differences in their mobilities in said high and low field conditions, and
• passing species of said ions through the filter according to the duty cycle for detection of said species at the output part.