Segmented Electrodes for FAIMS Ion Transmission and Resolving Power
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Solution Overview
Problem
Current FAIMS devices face limitations in achieving satisfactory mass spectrometry performance without FAIMS separation, particularly in transparent mode, due to the use of non-ideal waveforms and pressure conditions, which restricts ion transmission and resolving power.
Innovation Solution
A device with segmented planar electrodes that operates in both FAIMS and transparent modes, utilizing asymmetric time-dependent electric fields and adjustable gas pressures to enhance ion focusing and transmission, allowing for variable focusing strength and improved resolving power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If FAIMS separation is activated using conventional bisinusoidal waveforms, then ion separation performance is improved, but ion transmission efficiency deteriorates
Solution Approach 1:
The patent applies dynamics by making the electric field configuration dynamically switchable between segmented (for separation) and uniform (for transmission) modes. The segmented electrodes can be independently controlled to create asymmetric waveforms for separation or uniform fields for transparent mode, allowing the system to adapt its field structure based on operational requirements without mechanical adjustments.
Solution Approach 2:
The patent changes the waveform parameters from conventional bisinusoidal to asymmetric waveforms with optimized duty cycles and amplitude ratios. By adjusting the waveform shape, frequency, and amplitude parameters independently for each electrode segment, the system achieves high resolving power while maintaining ion transmission through optimized parameter selection rather than physical modification.
2Quantity of substance
If FAIMS device operates in transparent mode with conventional waveforms, then ion transmission is improved, but resolving power deteriorates
Solution Approach 1:
The patent achieves universality by designing the segmented electrode system to perform multiple functions: it can operate in separation mode with asymmetric waveforms for high resolving power, or switch to transparent mode with uniform waveforms for high ion transmission. The same physical device structure supports both analytical modes without requiring mechanical removal or modification of components.
Solution Approach 2:
The system dynamically reconfigures the electric field by applying different voltage patterns to the segmented electrodes. In transparent mode, all segments receive identical waveforms creating a uniform field for maximum transmission; in separation mode, segments receive differentiated asymmetric waveforms to create the field gradients necessary for resolving power.
3Measurement precision
If ideal rectangular waveform is used, then resolving power is improved, but device complexity increases
Solution Approach 1:
The patent segments the electrodes into multiple independent elements that can be controlled separately. This segmentation allows the complex asymmetric waveform to be generated by combining simpler voltage patterns applied to different segments, rather than requiring a single complex waveform generator. Each segment can be controlled with relatively simple waveforms that collectively produce the ideal rectangular-like field pattern.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The device achieves high ion transmission and resolving power simultaneously, enabling flexible operation between separation and transparent modes without mechanical adjustments, thus overcoming previous limitations in FAIMS technology.
Implementation Method 1
Field asymmetric waveform ion mobility spectrometry (FAIMS) is an established non-linear IMS method to separate ions by differences of mobility in gases as a function of electric field intensity
Implementation Method 2
propelling means for propelling ions through the analytical gap in a direction parallel to the analytical axis of the device
Implementation Method 3
a confining electric field in the analytical gap for focussing ions towards the longitudinal axis
Data Source
AI summary
A device for performing field asymmetric waveform ion mobility spectrometry, “FAIMS” including first and second segmented planar electrodes, each electrode including three or more segments and extending in a direction parallel to an analytical axis of the device, the first and second segmented electrodes are separated from each other to provide an analytical gap therebetween; and propelling means for propelling ions through the analytical gap in a direction parallel to the analytical axis. The device is configured to operate in: a FAIMS mode in which a power supply applies voltage waveforms to the segments to produce an asymmetric time dependent electric field in the analytical gap for FAIMS analysis of ions propelled through the analytical gap; and a transparent mode in which the power supply applies voltage waveforms to the to produce a confining electric field in the analytical gap for focussing ions towards the longitudinal axis.