Integrated oscillating field ion spectroscopy device and method of using same

Abstract

The integrated oscillating-field ion spectroscopy device includes an ionization segment, a filtering segment, and a detection segment arranged in sequence. The filtering segment is positioned after the ionization segment, and the detection segment is positioned after the filtering segment in the direction of carrier gas flow. The ionization segment includes an ionization tool and an ionization region electrode. The carrier gas moves a material vapor through the ionization tool to ionize the material vapor. Two parallel filter electrodes in the filtering segment receive a first DC voltage and an RF oscillating voltage of opposite polarity and filter ions from the carrier gas. Two parallel detector electrodes in the detection segment, connected to a detection system, receive a second DC voltage. Ion-guiding electrodes surround the detector electrodes. The DC voltage and RF oscillating voltage are selected to optimize detection of specific ions of interest for a particular application.

Description

[Technical Field]

[0001] STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT [1] This invention was made with government support under Grant No. R44AI141264 awarded by the National Institute of Allergy and Infectious Diseases. The government has certain rights in this invention. [Background technology]

[0002] background [2] The ability to detect and identify a variety of materials, including infection and disease biomarkers, drugs, hazardous chemicals, biological agents, and air pollution, has become increasingly important to human safety and well-being. Mass spectrometry and field asymmetric ion mobility spectrometry (FAIMS) (or IMS or DMS) have been used to detect and identify a variety of materials. Improved detection methods and portable, inexpensive material detection and identification methods and devices are desirable. Summary of the Invention [Means for solving the problem]

[0003] overview

[11] According to some embodiments of the present disclosure, an integrated oscillating-field ion spectroscopy device includes a chamber divided into at least three connected segments, including an ionization segment, a filtration segment, and a detection segment, arranged in sequence. The filtration segment is located downstream of the ionization segment in a carrier gas flow direction, and the detection segment is located downstream of the filtration segment in a carrier gas flow direction. The ionization segment includes a first opening and a second opening, where a carrier gas flows through the first opening into a first channel region in the ionization segment, and a material vapor flows through the second opening into the first channel region of the ionization segment. An ionization tool is mounted within the first channel region configured to ionize the material vapor. Two parallel ionization region electrodes on opposing walls of the first channel region are connected to a first DC voltage source or to ground, and the two parallel ionization region electrodes are configured to prevent charging of dielectric surfaces within the ionization segment. The filtration segment includes two parallel filter electrodes on opposing walls of a second channel region of the filtration segment parallel to the carrier gas flow direction. The two parallel filter electrodes are connected to a second DC voltage source to receive a second DC voltage of opposite polarity, and the two parallel filter electrodes are connected to a radio frequency (RF) voltage source to receive an RF oscillating voltage in addition to the second DC voltage. The two parallel filter electrodes are configured to generate an electric field due to the second DC voltage and the RF oscillating voltage to filter ions passing from the ionization segment. The detection segment includes two parallel detector electrodes on opposing walls of a third channel region of the detection segment parallel to the flow direction of the carrier gas. The two parallel detector electrodes are connected to a third DC voltage source to receive a third DC voltage and are connected to a detection system. The two parallel detector electrodes are configured to generate an electric field due to the third DC voltage to attract the filtered material vapor ions. Two parallel ion-guiding electrodes are on opposing walls of the third channel region and surround the detector electrodes. The two parallel ion guiding electrodes are connected to a fourth DC voltage source to receive a fourth DC voltage, and the two parallel ion guiding electrodes are configured to generate an electric field to guide ions toward the two parallel detector electrodes.The detection segment is configured to count the number of positive and negative ions in the material vapor. The first channel region, the second channel region, and the third channel region are arranged along a line and form a single channel. In one embodiment, the integrated oscillating-field ion spectroscopy device includes a first interface between the ionization segment and the filtering segment, the ionization segment having a transition region adjacent to the first interface, and the width of the transition region tapering from a first width to a second width, the second width being the width of the first interface, and the second width being 2 to 5 times smaller than the first width. In one embodiment, the integrated oscillating-field ion spectroscopy device includes one or more ground shields on an outer surface of the detection segment. In one embodiment, the integrated oscillating-field ion spectroscopy device includes an observation window, and the ionization zone is visible through the observation window. In one embodiment, the ionization tool includes a plasma source such as a cross-wire capacitive discharge device. In one embodiment, the electric field generated by a second DC voltage of opposite polarity in the second channel region has a direction opposite to that of the electric field generated by a third DC voltage in the third channel region. In one embodiment, the outer wall of the chamber includes two parallel ionization region electrodes, two parallel filter electrodes, two parallel detector electrodes, two parallel ion guide electrodes, and a plurality of connection pads electrically connected to each one of the ionization tool. In one embodiment, the integrated oscillating-field ion spectroscopy device includes a control system coupled to the first, second, third, and fourth DC voltage sources, the RF voltage source, and the detection segment, the control system being configured to control the second DC voltage source to adjust the second DC voltage and to adjust the amplitude or frequency of the RF oscillating voltage of the RF voltage source, and to control the first DC voltage, the third DC voltage, and the fourth DC voltage. In one embodiment, the electric field generated by the second DC voltage of opposite polarity in the second channel region has a direction that is the same as the electric field generated by the third DC voltage in the third channel region. In one embodiment, the ionization segment includes a first opening and a second opening, and the carrier gas flows through the first opening into the ionization segment and the material vapor flows through the second opening into the ionization segment.

[0004]

[12] According to some other embodiments of the present disclosure, an oscillating-field ion spectroscopy system includes an integrated oscillating-field ion spectroscopy device and an ionization device coupled to the integrated oscillating-field ion spectroscopy device along a gas flow. The ionization device includes an ionization tool mounted within the ionization device and configured to ionize a material vapor, and two parallel ionization region electrodes on opposing walls of the ionization device. The two parallel ionization region electrodes are connected to a first DC voltage source or ground, and the two parallel ionization region electrodes are configured to prevent charging of dielectric surfaces within the ionization device. The integrated oscillating-field ion spectroscopy device includes a chamber divided into at least two connecting segments, each including a filtering segment and a detection segment, arranged in sequence. The detection segment is positioned after the filtering segment in the carrier gas flow direction, and the filtering segment is positioned downstream of the ionization device. The filtering segment includes two parallel filter electrodes on opposing walls of a first channel region of the filtering segment parallel to the carrier gas flow direction. The two parallel filter electrodes are connected to a second DC voltage source to receive a second DC voltage of opposite polarity, and the two parallel filter electrodes are connected to a radio frequency (RF) voltage source to receive an RF oscillating voltage in addition to the second DC voltage. The two parallel filter electrodes are configured to generate an electric field by the second DC voltage and the RF oscillating voltage to filter ions passing from the ionization device. The detection segment includes two parallel detector electrodes on opposing walls of the second channel region of the detection segment parallel to the flow direction of the carrier gas. The two parallel detector electrodes are connected to a third DC voltage source to receive a third DC voltage and are connected to a detection system. The two parallel detector electrodes are configured to generate an electric field by the third DC voltage to attract material vapor ions, and the detection system is configured to determine the number of positive and negative ions of the material vapor. Two parallel ion-guiding electrodes are on opposing walls of the second channel region and surround the detector electrodes. The two parallel ion guiding electrodes are connected to a fourth DC voltage source to receive a fourth DC voltage, and the two parallel ion guiding electrodes are configured to generate an electric field to guide ions toward the two parallel detector electrodes.In one embodiment, the first channel region and the second channel region are arranged along a line and form a single channel. In one embodiment, an electric field generated by a second DC voltage of opposite polarity in the first channel region has a direction opposite to that of an electric field generated by a third DC voltage in the second channel region. In one embodiment, the outer wall of the chamber includes two parallel filter electrodes, two parallel detector electrodes, and a plurality of connection pads electrically connected to each one of the two parallel ion-guiding electrodes. In one embodiment, the integrated oscillating-field ion spectroscopy device is a replaceable component of an oscillating-field ion spectroscopy system. In one embodiment, the oscillating-field ion spectroscopy system includes one or more shield grounds disposed on an outer surface of the detection segment. In one embodiment, the oscillating-field ion spectroscopy system includes a control system coupled to the second, third, and fourth DC voltage sources, the RF voltage source, and the detection segment, the control system being configured to control the second voltage source to adjust the second DC voltage and to adjust the amplitude or frequency of the RF oscillating voltage of the RF voltage source, and configured to control the second DC voltage, the third DC voltage, and the fourth DC voltage.

[0005]

[13] According to some other embodiments of the present disclosure, an integrated oscillating-field ion spectroscopy device includes a chamber divided into at least two connecting segments, including a filtration segment and a detection segment, with the detection segment being disposed downstream of the filtration segment in the carrier gas flow direction. The filtration segment includes two parallel filter electrodes on opposing walls of the filtration segment channel region parallel to the carrier gas flow direction. The two parallel filter electrodes are connected to a first DC voltage source to receive a first DC voltage of opposite polarity and to an RF voltage source to receive an RF oscillating voltage. The detection segment includes two parallel detector electrodes on opposing walls of the detection segment channel region parallel to the carrier gas flow direction. The two parallel detector electrodes are connected to a second DC voltage source to receive a second DC voltage. The detection segment is configured to determine the number of positive and negative ions in the material vapor. Two parallel ion-guiding electrodes are located on opposing walls of the detection segment channel region. The ion-guiding electrodes surround the detector electrodes. The two parallel ion directing electrodes are connected to a third DC voltage source to receive a third DC voltage, and the two parallel ion directing electrodes are configured to generate an electric field to direct ions toward the two parallel detector electrodes. In one embodiment, the integrated oscillating-field ion spectroscopy device includes an ionization segment upstream of the filtration segment along a carrier gas flow direction, the ionization segment including one or more inlets within the ionization segment channel region, an ionization segment channel region, and an ionization source selected from the group consisting of a cross-wire capacitive discharge ionizer, an ultraviolet ionizer, an electrospray ionizer, a radioactive ionizer, and combinations thereof. The ionization source is configured to ionize the material vapor. The two parallel ionization region electrodes are on opposite walls of the ionization segment channel region. The two parallel ionization region electrodes are connected to a fourth DC voltage source or to ground, and the two parallel ionization region electrodes are configured to prevent charging of dielectric surfaces within the ionization segment. In one embodiment, the height of the filtration segment channel region is less than the height of the ionization segment channel region, and the height of the detection segment channel region is greater than the height of the filtration segment channel region.

[0006]

[14] According to some other embodiments of the present disclosure, there is provided a method of operating an integrated oscillating-field ion spectroscopy system including an integrated oscillating-field ion spectroscopy device, the integrated oscillating-field ion spectroscopy device including a chamber divided into at least three segments, including an ionization segment, a filtering segment, and a detection segment, arranged sequentially in a flow direction of a carrier gas. The method includes flowing a mixture of the carrier gas and material vapor ions with the carrier gas through the filtering segment and the detection segment. At least a portion of the material vapor in an ionization zone of the ionization segment is ionized to produce material vapor ions in the mixture. A first DC voltage or ground is applied to two parallel ionization region electrodes on opposing walls of the ionization segment. At least a portion of the ions in the mixture other than the material vapor ions are filtered by simultaneously applying an RF oscillating voltage and a second DC voltage of opposite polarity to two parallel filter electrodes on opposing walls of the filtering segment. The material vapor ions are detected by applying a third DC voltage to two parallel detector electrodes on opposing walls of the detection segment and by applying a fourth DC voltage to two parallel ion-guiding electrodes, the two parallel ion-guiding electrodes surrounding the two parallel detector electrodes. In one embodiment, the method includes providing a carrier gas from a carrier gas source through a first opening in the ionization segment, the carrier gas flowing the material vapor into the ionization zone; and providing a reformulating gas to the ionization segment through a second opening. In one embodiment, the method includes mixing the carrier gas and the material vapor in the ionization segment. In one embodiment, filtering at least a portion of the ions other than the material vapor ions in the mixture includes discharging the ions other than the material vapor ions through two parallel detector electrodes on opposing walls of the filtering segment. In one embodiment, the method includes separating the positive and negative ions by simultaneously applying an RF oscillating voltage and a second DC voltage to two parallel filter electrodes on opposing walls of the filtering segment. In one embodiment, the method includes removing an integrated oscillating field ion spectroscopy device from a system when the sensitivity of the device falls below a threshold and installing a replacement integrated oscillating field ion spectroscopy device in the system.

[0007]

[15] According to some embodiments of the present disclosure, there is provided a method of operating an integrated oscillating-field ion spectroscopy system including an integrated oscillating-field ion spectroscopy device, the integrated oscillating-field ion spectroscopy device including a chamber divided into at least two segments, including a filtering segment and a detecting segment arranged in sequence, the detecting segment being disposed after the filtering segment in a flow direction of the carrier gas. The method includes flowing a mixture of the carrier gas and material vapor ions through the filtering segment and the detecting segment with the carrier gas. At least a portion of ions other than the material vapor ions in the mixture are filtered by simultaneously applying an RF oscillating voltage and a first DC voltage of opposite polarity to two parallel filter electrodes on opposing walls of the filtering segment. The material vapor ions are detected by applying a second DC voltage to two parallel detector electrodes on opposing walls of the detecting segment and a third DC voltage to two parallel ion guiding electrodes on opposing walls of the detecting segment, the ion guiding electrodes surrounding the detector electrodes. In one embodiment, the method includes providing a modifying gas to the mixture of the carrier gas and material vapor ions. In one embodiment, filtering at least a portion of the ions other than the material vapor ions in the mixture includes discharging the ions other than the material vapor ions through two parallel filter electrodes on opposing walls of the filtering segment. In one embodiment, the method includes separating the positive and negative ions by simultaneously applying an RF oscillating voltage and a first DC voltage to two parallel filter electrodes on opposing walls of the filtering segment. In one embodiment, the method includes removing the integrated oscillating field ion spectroscopy device from the system when the sensitivity of the device falls below a threshold and installing a replacement integrated oscillating field ion spectroscopy device in the system.

[0008] BRIEF DESCRIPTION OF THE DRAWINGS [3] The present disclosure is best understood from the following detailed description when read in conjunction with the accompanying drawings. It may be emphasized that, according to standard industry practice, various features are not drawn to scale and are used for illustrative purposes only. In fact, the dimensions of various features may be arbitrarily increased or decreased for clarity of discussion. [Brief explanation of the drawings]

[0009] [Figure 1A] [4] An oscillating field ion spectrometry (OFIS) system including an integrated OFIS device and peripherals of the integrated OFIS device, and a waveform of a periodic strong asymmetric RF voltage applied to the OFIS device are shown. [Figure 1B] [4] An oscillating field ion spectrometry (OFIS) system including an integrated OFIS device and peripherals of the integrated OFIS device, and a waveform of a periodic strong asymmetric RF voltage applied to the OFIS device are shown. [Figure 1C] [4] An oscillating field ion spectrometry (OFIS) system including an integrated OFIS device and peripherals of the integrated OFIS device, and a waveform of a periodic strong asymmetric RF voltage applied to the OFIS device are shown. [Figure 2A] [5] A top view of a three-segment integrated OFIS device is shown. [Figure 2B] [5] A cross-sectional view along line BB in Figure 2A is shown. [Figure 2C] [5] A cross-sectional view along line CC in Figure 2A is shown. [Figure 2D] [5] shows a plan view of a two-segment integrated OFIS device. [Figure 2E] [5] A cross-sectional view along line DD in Figure 2D is shown. [Figure 2F] [5] A cross-sectional view illustrating the motion of ions according to an embodiment of the present disclosure. [Figure 3A] [6] An integrated OFIS device according to an embodiment of the present disclosure is shown. [Figure 3B] [6] An integrated OFIS device according to an embodiment of the present disclosure is shown. [Figure 3C] [6] An integrated OFIS device according to an embodiment of the present disclosure is shown. [Figure 3D] [6] An integrated OFIS device according to an embodiment of the present disclosure is shown. [Figure 3E] [6] An integrated OFIS device according to an embodiment of the present disclosure is shown. [Figure 4] [7] shows a flow diagram of a method for operating an OFIS device according to some embodiments of the present disclosure. [Figure 5A] [8] shows the ionization segment of an integrated OFIS device. [Figure 5B] [8] shows the ionization segment of an integrated OFIS device. [Figure 5C] [8] shows the ionization segment of an integrated OFIS device. [Figure 6] [9] shows a flow diagram of a method for operating an OFIS system according to some embodiments of the present disclosure. [Figure 7]

[10] Figure 1 shows a flow diagram of a method for operating an OFIS system according to some embodiments of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010] Detailed Description

[16] It will be understood that the following disclosure provides many different embodiments or examples for implementing various features of the present invention. Specific embodiments or examples of components and arrangements are described below to simplify the disclosure. These are, of course, merely examples and are not intended to be limiting. For example, element dimensions are not limited to the disclosed ranges or values ​​but may depend on the process conditions and / or desired characteristics of the device. Furthermore, references to forming a first feature on or over a second feature in the following specification may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed between the first and second features such that the first and second features are not in direct contact. Various features may be arbitrarily drawn to different scales for simplicity and clarity.

[0011]

[17] Furthermore, spatially relative terms such as “below,” “lower,” “lower side,” “above,” and “upper” may be used herein for ease of description to describe the relationship of one element or feature to another element or feature shown in the accompanying figures. These spatially relative terms are intended to encompass various orientations of the device in use or operation in addition to the orientation depicted in the accompanying figures. A device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptions used herein may likewise be interpreted accordingly. Additionally, the term “made of” may mean either “comprising” or “composed of.” In this disclosure, the phrase “one of A, B, and C” means “A, B, and / or C” (A, B, C, A and B, A and C, B and C, or A, B, and C), but does not mean one element from A, one element from B, and one element from C, unless otherwise specified.

[0012]

[18] Differentiating various materials with oscillating field ion spectroscopy (OFIS) has become important because OFIS devices are smaller, portable, and cheaper to procure and operate, less complex, use significantly less power, and do not require high vacuum to operate compared to mass spectrometers. OFIS devices according to embodiments of the present disclosure provide higher detection sensitivity due to increased ion transmission efficiency without sacrificing specificity. OFIS devices according to embodiments of the present disclosure have performance with reduced false negatives and false positives compared to FAIMS devices. OFIS devices according to embodiments of the present disclosure avoid the loss of sensitivity caused by micro-deposits in the analytical channel and surface charging that occurs in FAIMS devices. Fabrication and testing of OFIS devices according to embodiments of the present disclosure are simpler and cheaper than FAIMS devices. Additionally, OFIS devices according to embodiments of the present disclosure have an extended operating temperature range compared to FAIMS devices. Furthermore, OFIS devices according to embodiments of the present disclosure are replaceable. If the sensitivity of an OFIS system falls below a threshold, the OFIS device can be quickly and economically replaced. The ion transfer efficiency losses, gas path leakage, and higher assembly costs of FAIMS devices are reduced or eliminated in OFIS devices according to embodiments of the present disclosure. OFIS devices according to embodiments of the present disclosure provide ultra-trace (e.g., less than 1 ppm) detection and identification of chemical vapors of interest.

[0013]

[19] In an integrated OFIS device, first, second, and third segments (or regions) are arranged side by side in a row. The first region is an ionization segment, where a material vapor, identified along with a carrier gas, flows through the ionization segment. The ionization segment includes a plasma generation region, where plasma is generated from the gas flowing through the ionization segment. The plasma generation region generates ions from the material vapor and the carrier gas. Other ions can be generated in the plasma generation region, including modified ions, fragment ions, environmental ions, contaminant ions, and ions of additional materials that may be present in the sample. In some embodiments, a portion of the material vapor and a portion of the carrier gas are ionized, and the remaining portion of the collected material and carrier gas is not ionized. The second region is a filtration segment, located adjacent to the ionization segment along the direction of carrier gas flow. In some embodiments, the carrier gas transports ions from the ionization segment to the filtration segment. The third region is a detection segment, located adjacent to the filtration segment along the direction of carrier gas flow. In some embodiments, the carrier gas transports ions from the filtration segment to the detection segment. In some embodiments, all gases and vapors, including carrier gas, modifying gas, and material vapor, exit the OFIS device through the detection segment, hi some embodiments, the first, second, and third segments comprise a single channel through the ionization segment, filtration segment, and detection segment.

[0014]

[20] The filtering segment includes two parallel electrodes on opposing walls of the filtering segment parallel to the direction of carrier gas flow (e.g., on the top and bottom walls or on opposing side walls). The two electrodes are connected to a voltage source that provides opposite-polarity DC voltages to the two electrodes. The two electrodes are additionally connected to a radio frequency (RF) voltage source that provides an RF oscillating voltage to the two electrodes in addition to the DC voltage. As the carrier gas carries ions from the material vapor between the two electrodes, the positive and negative ions experience forces due to the electric field generated by the DC and RF voltages between the two electrodes and move in opposite directions when the RF voltage changes from positive to negative. In some embodiments, the combination of the opposite-polarity DC voltage and the RF oscillating voltage causes unwanted ions, such as carrier gas ions or ions of materials other than the material vapor ions, to reach the two parallel electrodes of the filtering segment and are discharged while the carrier gas and material vapor ions are passed through the parallel electrodes. Thus, some of the ions are removed, e.g., filtered, from the flowing carrier gas to provide a filtered material vapor. In some embodiments, ions of the material vapor are not discharged as they flow from the filtration segment to the detection segment, hi some embodiments, the unwanted ions include ions of contaminants that entered the ionization segment or ions of the material that forms the ionization segment.

[0015]

[21] The detection segment includes two parallel electrodes similar to those of the filtration segment on opposing walls of the detection segment parallel to the direction of carrier gas flow (e.g., on the top and bottom walls or on opposing side walls). The two electrodes are connected to a voltage source that provides a DC voltage to the two electrodes of the detection segment. In some embodiments, DC voltages of opposite polarity are applied to the opposing parallel electrodes. The two parallel electrodes of the detection segment are additionally connected to a detection system that detects (e.g., registers or counts) the number of ions that impinge on and are discharged from the two parallel electrodes of the detection segment. In some embodiments, the detection system is a charge detector. In some embodiments, positive ions are discharged by one of the two parallel electrodes, and negative ions are discharged by the other of the two parallel electrodes of the detection segment, and the detection system detects the number of positive and negative ions, for example, based on the number of ions registered and discharged by the two electrodes. Ions of additional unidentified material may be detected. Detection information of the unidentified material may be stored in the memory of the OFIS system for subsequent identification and analysis, if desired.

[0016]

[22] In some embodiments, the DC voltages of the two electrodes of the detection segment, the DC voltages of the two electrodes of the filtration segment, and the RF voltage and RF frequency applied between the two electrodes of the filtration segment are adjusted based on the mobility of the ions of the material vapor and the mobility of unwanted ions (e.g., carrier gas ions). The RF and DC voltages of the filtration segment are selected to optimize the sensitivity and selectivity of the OFIS device. For example, a higher RF voltage increases ion separation and therefore selectivity. However, increasing the RF voltage may reduce sensitivity. Adjusting the RF and DC voltages discharges (e.g., removes) a portion of the unwanted ions in the filtration segment and allows the remaining portion of the unwanted ions, along with the desired ions, unknown ions, and neutrals, to pass through the parallel electrodes of the detection segment. As discussed above, when filtering unwanted ions, ions are discharged in the filtration segment and therefore not detected by the detection system in the detection segment, but the discharged ions are carried by the carrier gas.

[0017] 1A shows an oscillating field ion spectroscopy system 110 including an OFIS device (or sensor) 100 and peripherals of the OFIS system. The OFIS device (or sensor) 100 includes a chamber 155 having, in some embodiments, three segments: an ionization segment 102, a filtration segment 104, and a detection segment 106. The ionization segment 102 is connected to the filtration segment 104 via an interface 112. The ionization segment 102 includes a first opening 124 that is connected to a pipe 128. A carrier gas flow 152 enters the ionization segment 102 via the pipe 128 from a carrier gas source 116 external to the OFIS device 100. In some embodiments, the carrier gas source 116 comprises nitrogen, argon, air, or any suitable gas.

[0018] As shown, the ionization segment 102 also includes a second opening 126 connected to a pipe 108 leading to a material vapor stream 154. The material vapor stream enters the ionization segment 102 via the pipe 108 from a material supply 118 external to the OFIS device 100. In some embodiments, the material supply 118 contains one or more material vapor samples, including biomarkers of infection and disease, drugs, hazardous chemicals, biological agents, breath, or contaminated air. The material vapor stream 154 can contain substantially only the material vapor to be sampled, or the material vapor to be sampled can be mixed with a carrier gas, such as air, to provide the material vapor stream 154. In some embodiments, the material supply 118 receives the material via a pipe 162. In some embodiments, a stream of nitrogen and / or air containing the material to be sampled enters the material supply 118 via the pipe 162 and generates the material vapor stream 154. In some embodiments, the material is in gaseous, liquid, or solid form inside material supplier 118. A stream of nitrogen and / or air enters material supplier 118 via pipe 162, mixes with the material, and produces material vapor stream 154. In some embodiments, the material to be collected is introduced intermittently into ionization segment 102. In some embodiments, the material to be collected is breath.

[0019]

[25] Material vapor flow 154 and carrier gas flow 152 are mixed within the ionization segment, the mixture is ionized by ionization tool 125 (e.g., an ionization source), and the mixture includes ions of the material stream sampled from ionization segment 102 via interface 112 as gas flow 156. The ionization segment is described in more detail with respect to Figures 2A and 2B. In some embodiments, gas flow 156 is a combination of sampled gas flow 154 and carrier gas flow 152, which is at least partially ionized.

[0020]

[26] In some embodiments, the ionization segment 102 includes an additional third opening 182 connected to a pipe 190. A reformulated gas stream 191 passes from a reformulated gas supply 170 outside the ionization segment 102, which is outside the OFIS device 100, through the opening 182 and enters the ionization segment 102 via the pipe 190. In some embodiments, a stream of nitrogen and / or air containing reformulated gas enters the reformulated gas supply 170 via the pipe 161 and generates (e.g., produces) the reformulated gas stream 191. In some embodiments, the reformulated gas is in gaseous, liquid, or solid form inside the reformulated gas supply 170. The nitrogen and / or air stream entering the reformulated gas supply 170 via the pipe 161 mixes with the reformulated gas and produces the reformulated gas stream 191. In some embodiments, the reformulated gas includes a dopant. In some embodiments, the modifying gas stream 191 alters ion chemistry to enhance and / or suppress ionization of one or more atoms or compounds. In some embodiments, the modifying gas is selected so that it does not ionize within the ionization segment 102. In some embodiments, the modifying gas is a suitable solvent. The modifying gas may include, but is not limited to, one or more selected from the group consisting of water, acetonitrile, acetone, ethyl acetate, propyl acetate, n-butyl acetate, methanol, ethanol, 1-propanol, 2-propanol, methylene chloride, and cyclohexane. The modifying gas may modify the ions (including changing the structure of the ions). In some embodiments, the modifying gas may alter the molecular weight of the collected material by either clustering the collected material (i.e., increasing its molecular weight) or fragmenting the collected material (i.e., decreasing its molecular weight). In some embodiments, the counterflow enters the ionization segment 102 through a fourth opening (not shown) and exits through a fifth opening (not shown). In some embodiments, counterflow allows the carrier gas, sample, and modified gas streams to flow in opposite directions, helping to suppress chemical noise. Detection of ions is described with respect to Figure 2F. In other embodiments, no modified gas is used, and therefore the ionization segment 102 does not include a modified gas inlet port.

[0021]

[27] In some embodiments, in addition to the material vapor, ions of the carrier gas flow 152 and the modifying gas flow 191 are also ionized by the ionization tool 125, producing carrier gas ions and modifying ions. In some embodiments, the carrier gas or modifying gas is ionized in the ionization zone 210 of the ionization tool 125 (see FIG. 2B), and the ionized carrier gas or modifying gas then ionizes the material vapor. Thus, the gas flow 156 may contain ions of the material vapor, the carrier gas, and the modifying gas (see the configurations of FIGS. 5A, 5B, and 5C). In some embodiments, the carrier gas ions or the modifying gas are undesired. Therefore, the oscillating field ion spectroscopy system 110 and the OFIS device 100 are designed to prevent the carrier gas and the modifying ions from interfering with the identification of the type of material vapor and the determination of the amount of material vapor. As shown, two or more voltages are applied to the ionization segment 102 from the voltage source 120 via two or more electrical connections (e.g., connections 194a, 194b). The two or more voltages are applied to the ionization tool 125 to ionize the collected material and / or carrier gas. In some embodiments, two ionization region electrodes 255A, 255B are disposed on opposite sidewalls of the ionization segment 102. The two ionization region electrodes 255A and 255B are parallel to each other and extend along the flow direction of the carrier gas and material vapor. In some embodiments, the parallel ionization region electrodes 255A, 255B are connected to the DC voltage source 120 via two or more connections 185a, 185b. In some embodiments, DC voltage source 120 includes multiple DC voltage sources (e.g., a first DC voltage source, a second DC voltage source, a third DC voltage source, etc.), where each DC voltage source provides a DC voltage to a different pair of opposing electrodes (e.g., ionization region electrodes 255A, 255B, filter electrodes 216A, 216B, detection electrodes 204A, 204B, induction electrodes 265A, 265B). In other embodiments, ionization region electrodes 255A, 255B are connected to ground. The ionization region electrodes prevent charging of dielectric surfaces within ionization segment 102.

[0022]

[28] In some embodiments, other materials, such as contaminants, are present in the ionization segment. In such embodiments, the contaminants may also be ionized. In some embodiments, outgassing within the OFIS device creates contaminants. Contaminants can affect the sensitivity and results provided by the detection system 140. Therefore, in some embodiments, the carrier gas source 116, material supply 118, pipes 161, 162, 128, 108, and components within the ionization segment 102 are designed and selected to prevent outgassing. In some embodiments, the carrier gas flow is between about 50 milliliters (ml) per minute (min) and about 500 ml / min. In some embodiments, the carrier gas flow is between about 100 ml / min and about 150 ml / min. In some embodiments, the carrier gas is air, nitrogen, helium, hydrogen, any suitable gas, or a combination of two or more gases.

[0023] 1A, OFIS device 100 includes filtering segment 104. Filtering segment 104 receives gas flow 156 containing ions of a material vapor via interface 112. In some embodiments, ions of a carrier gas or reformulating gas and the material vapor are generated by ionization tool 125, and thus, ions of the carrier / reformulating gas and the material vapor are present in gas flow 156. An electric field is generated within filtering segment 104 by applying a voltage between an electrode (e.g., electrode 216A and 216B in FIG. 2B) of filtering segment 104 and DC voltage source 120 and RF source 130 via two or more electrical connections (e.g., connections 197a, 197b, 207a, 207b). In some embodiments, DC voltage source 120 and RF source 130 share a common connection to the electrode. Thus, the RF source generates an RF voltage between electrodes 216A and 216B, and DC voltage source 120 additionally generates a DC voltage between electrodes 216A and 216B. The electric field direction and strength are adjusted to remove unwanted ions for application from gas flow mixture 156. Thus, ions other than the specific ions of the material vapor are discharged by contacting the electrodes of the filtration segment. In some embodiments, while the carrier gas ions and the modified ions are discharged within filtration segment 104, some carrier gas ions, modified ions, and neutral atoms or molecules may remain in carrier gas flow 156 as they pass through detection segment 106. Filtration segment 104 is connected to detection segment 106 via interface 114. In some embodiments, gas flow 158, which is a continuation of gas flow 156, flows through interface 114 between filtration segment 104 and detection segment 106. In some embodiments, a portion of the ions in gas flow 156 are discharged within filtration segment 104, and gas flow 158 is generated. The filtration segment 104 is described in more detail with respect to Figures 2A, 2B and 2C.

[0024] 1A, OFIS device 100 includes detection segment 106. Detection segment 106 receives gas flow 158 containing ions of a material vapor via interface 114. An electric field is generated within detection segment 106 by applying a voltage between voltage source 120 and detector electrodes (e.g., detector electrodes 204A, 204B in FIG. 2B, which are used to detect ions in detection segment 106) via two or more electrical connections (e.g., connections 192a, 192b). Electrical connections 192a, 192b are connected to detection system 140, which is disposed between voltage source 120 and detection segment 106. Two or more electrical connections 184a, 184b connect detection system 140 to connection pads 144a, 144b of detector electrodes 204A, 204B.

[0025]

[31] The electric field direction and strength are adjusted so that ions of the sampled material in the gas stream 158 are discharged by the electrodes 204A, 204B of the detection segment 106. The detector electrodes 204A, 204B of the detection segment 106 are connected to the detection system 140 via two or more electrical connections 184a, 184b. In some embodiments, the detection system 140 is a charge detector that determines the amount of charge absorbed by the electrodes. Based on the amount of charge absorbed by the electrodes of the detection system 140, the detection system determines the amount of ions (e.g., amount of ions / time, current) discharged by the electrodes of the detection segment 106.

[0026]

[32] In some embodiments, two ion-guiding electrodes 265A, 265B are positioned parallel to each other on opposite sidewalls of the detection segment 106. The ion-guiding electrodes 265A, 265B surround the detector electrodes 204A, 204B. In some embodiments, the ion-guiding electrodes 265A, 265B are connected to the DC voltage source 120 by two or more connection wires 188a, 188b via corresponding connection pads 145a, 145b. The ion-guiding electrodes 265A, 265B increase the efficiency of the detection segment 106 by directing material vapor ions toward the detector electrodes 204A, 204B. The ion-guiding electrodes 265A, 265B also prevent leakage current from the filtration segment 104 from affecting the detector electrodes 204A, 204B.

[0027]

[33] In some embodiments, DC voltage source 120 includes multiple DC voltage sources (e.g., a first DC voltage source, a second DC voltage source, a third DC voltage source, a fourth DC voltage source, etc.), where each DC voltage source provides a DC voltage to a different pair of opposing electrodes (e.g., ionization region electrodes 255A, 255B, filter electrodes 216A, 216B, detector electrodes 204A, 204B, ion-guiding electrodes 265A, 265B).

[0028]

[34] The detection segment 106 is described in more detail with respect to Figures 2A and 2B. The connecting lines described above (including connecting lines 184a, 184b, 185a, 185b, 188a, 188b, 192a, 192b, 194a, 194b, 197a, 197b, 207a, and 207b) may include two or more lines.

[0029] As described herein, the RF and DC voltages of the filtration segment can be selected to optimize the sensitivity and selectivity of the OFIS device. In some embodiments, ion flow depends on the charge and mobility of the ions. The detection segment 106 further includes an opening 142 connected to a pipe 146, and exhaust gas flow 160 exits the detection segment 106 via pipe 146 and enters a pump / filter device 117 outside of the OFIS device 100. The pump / filter device 117 extracts the exhaust gas flow 160 via its pump and filters it to remove material vapors and other residues from the material vapor flow 154, and returns the remaining carrier gas from the carrier gas flow 152 to the carrier gas source 116 via pipe 115. In some embodiments, pump / filter device 117 includes multiple stages of filters and / or pumps followed by another stage of filters and / or pumps, and pump / filter device 117 scrubs exhaust gas flow 160 in multiple stages. In some embodiments, pump / filter device 117 includes a pump and multiple filters stacked one on top of the other, and pump / filter device 117 scrubs exhaust gas flow 160 using the multiple filters. In some embodiments, pump / filter device 117 includes a pressure sensor 164 for monitoring the pressure within the OFIS device. A venting element / vent 163 may be provided within the pump / filter device to release pressure from the OFIS system and maintain a constant pressure. Maintaining a consistent pressure through the OFIS device provides consistent and reproducible results. In some embodiments, the components within pump / filter device 117 are arranged in the following order: venting element / vent 163 along the direction of exhaust gas flow 160, filter, pump, filter, pressure sensor.

[0030]

[36] In some embodiments, exhaust gas stream 160 also contains reformulated gas from reformulated gas stream 191, and pump / filter device 117 filters the reformulated gas. In some embodiments, each filter in pump / filter device 117 extracts one of the material vapors, the reformulated gas, or impurities, and a group of filters in pump / filter device 117 scrubs exhaust gas stream 160.

[0031]

[37] The oscillating field ion spectroscopy system 110 also includes a control system 180 coupled via control lines 123 and controlling the voltage source 120, the RF source 130, and the detection system 140. Based on the amount of discharge ions of the material vapor detected by the detection system 140, the control system 180 can adjust the output voltage of the voltage source 120 applied to the filtration segment 104 and the detection segment 106. The control system 180 can also adjust the frequency and amplitude of the output RF voltage applied to the filtration segment 104 based on the mobility of the carrier gas ions and the ions of the material vapor. The control system 180 can independently control the DC voltages applied to each of the ionization region electrodes 255A, 255B, the filter electrodes 216A, 216B, the detector electrodes 204A, 204B, and the ion guiding electrodes 265A, 265B. Additionally, control system 180 is connected via control lines 119 to the body of chamber 155 to control the temperature of chamber 155 via temperature monitoring using thermistor 222. Control system 180 also independently controls the pumps in pump / filter device 117, monitors the pressure sensed by pressure sensor 164, and / or opens and closes vent / vent 163 to control the pressure in the OFIS system via feedback control via control lines 199.

[0032]

[38] In some embodiments, the material of the pipes 190, 162, 161, 128, 115, 146, 108, or 163 is made of one of, but not limited to, stainless steel, silicon steel, polytetrafluoroethylene (PTFE), polyetheretherketone (PEEK), liquid crystal polymer (LCP), fluorocarbon rubber (e.g., Viton®), or ceramic (such as alumina).

[0033]

[39] In some embodiments, OFIS device or sensor 100 includes one or more exterior ground shields 220A, 220B on the exterior wall of chamber 155. The one or more ground shields 220A, 220B are described with reference to FIG. 2B. Voltage source 120 can be connected to one or more ground shields 220A, 220B via at least one connecting wire 121. The one or more ground shields 220A, 220B are described with reference to FIG. 2B. Also, in some embodiments, one or more surface heaters 225A, 225B are disposed (e.g., attached) on and connected to the exterior wall of chamber 155, and control system 180 is connected to the exterior surface heaters 225A, 225B via control wires 119. The one or more exterior surface heaters 225A, 225B are described with reference to FIG. 2C. In some embodiments, a thermistor 222 and one or more surface heaters (not shown) are also mounted on and connected to the exterior wall of the ionizing device 196, and the control system 180 is connected to the thermistor 222 and the exterior surface heaters via control lines 119. In the OFIS system 110, the three-segment OFIS device or sensor 100 is disposable and can be replaced with a replacement three-segment OFIS device as needed.

[0034] 1B shows an OFIS system 113 including a two-segment OFIS device 103 and surrounding equipment. The difference between OFIS system 113 and OFIS system 110 is that in OFIS system 113, the ionization segment 102 is not included in the two-segment OFIS device or sensor 103. The two-segment OFIS device 103 includes a filtration segment 104 and a detection segment 106. As shown in FIG. 1B, the ionization segment 102 and the ionization tool 125 are included in a separate ionization device 196, and the ionization segment 102 of the ionization device 196 is connected to the filtration segment 104 of the OFIS device 103 via an interface 112. A gas flow 156 is transferred between the ionization segment 102 of the ionization device 196 and the filtration segment 104 of the OFIS device 103 via the interface 112. In OFIS systems 113 that include a two-segment OFIS device 103, the two-segment OFIS device 103 is disposable and can be replaced with a replacement two-segment OFIS device independent of the ionization segment as needed.

[0035]

[41] Figure 1C is a waveform of a periodic, strongly asymmetric RF voltage. Figure 1C shows several periods of RF voltage by graph 175 displayed on a voltage axis 178 and a time axis 176. The RF voltage is applied to electrodes of filtering segment 104. Electrodes 216A, 216B of filtering segment 104 are shown in Figure 2B. As shown, the voltage from electrode 216A to electrode 216B varies between a positive voltage v2 and a negative voltage v1, such that a positive voltage v2 is applied for the period from time zero to time t1 and a negative voltage v1 is applied for the period from time t1 to time t2. In some embodiments, voltages v1 and v2 and times t1 and t2 are selected so that the area within one period of graph 175 with voltage v2 is equal to the area with voltage v1, and the net total area under the periods of graph 175 for voltage v1 and voltage v2 is zero. In some embodiments, the difference between the amplitudes of the RF voltages v2 and v1 (v2 - v1) is about 250 volts to about 2000 volts, and the frequency of the RF voltage is about 1 MHz to about 2 MHz. In other embodiments, the amplitude of the RF voltage is about 800 volts to 1500 volts. In some embodiments, the amplitudes of the RF voltages are equal and of opposite polarity on the opposing electrodes. For example, the voltages may be +750 V on one electrode and -750 V on the opposing electrode for a total voltage difference of 1500 V. In some embodiments, the time difference between t2 and t1 (t2 - t1) is about 3 to 5 times the period t1 (between t1 and time zero). In some embodiments, v2 is 1600 volts and v1 is -400 volts.

[0036]

[42] Figures 2A, 2B, and 2C show a schematic plan view, a cross-sectional view along line BB, and a cross-sectional view along line CC of a three-segment integrated OFIS device according to one embodiment of the present disclosure. Figure 2A shows a plan view 200 of the integrated OFIS device 100 of Figure 1A, illustrating the ionization segment 102, the filtration segment 104, and the detection segment 106.

[0037]

[43] The ionization segment 102 includes a first opening 124 and a second opening 126. In some embodiments, the ionization segment 102 includes an observation window 213 disposed over the ionization zone 210 of the ionization tool 125 of the ionization segment 102 so that an observer or sensor can observe the ionization zone 210 from outside the OFIS device 100. In some embodiments, the ionization tool 125 of the ionization segment 102 is an ionization source that produces carrier gas ions, modified gas ions, and sample gas ions. In some embodiments, the ionization source generates a plasma discharge environment within the ionization zone 210. In one example, the ionization source is a plasma source such as a cross-wire capacitive discharge device, which may include biased electrodes (not shown) connected to a voltage source 120 via connection pads 122a, 122b and via connection lines 194a, 194b (which may include additional connection lines). The ionization segment 102 includes a pair of parallel ionization region electrodes 255 A, 255 B on opposite sidewalls of the ionization segment channel 228 .

[0038]

[44] In some embodiments, the width W1 of the ionization segment channel 228 is about 0.25 cm to about 0.76 cm (about 0.1 inches to about 0.3 inches), and in other embodiments, the width W1 is about 0.38 cm to about 0.63 cm (about 0.15 inches to about 0.25 inches). As shown, the ionization segment 102 is connected to the filtration segment 104 via an interface 112. The interface 112 has a width W3 that is about 5 to 10 times smaller than the width W1. The ionization segment 102 has a transition zone 211 that tapers toward the interface 112. In some embodiments, the length of the transition zone 211 is about 1 / 3 to 1 / 4 of the length of the ionization segment 102 (i.e., comprising a transition zone 211 of about 0.63 cm to about 0.89 cm (about 0.25 inches to about 0.35 inches)). As shown in FIG. 2B , carrier gas flow 152 and / or sampling gas flow 154 flow through ionization segment channel 228. In some embodiments, ionization zone 210 is part of channel 228. The width of channel 228 narrows at transition zone 211. In some embodiments, connection pads 219 a, 219 b are used to connect voltage source 120 to ionization region electrodes 255A, 255B. In some embodiments, an ionized sample generated in another ionization source enters the ionization segment through aperture 126. In some embodiments, the other ionization source is a radioactive ionization source. In some embodiments, control system 180 controls the operation of ionization segment 102 and ionization tool 125.

[0039]

[45] Filtering segment 104 is also shown in FIG. 2A. As discussed herein, filtering segment 104 has two parallel electrodes 216A, 216B. FIG. 2A shows top electrode 216A, which is parallel to bottom electrode 216B (shown in FIG. 2B) disposed below it. Top and bottom electrodes 216A and 216B are connected to connection lines 197a, 197b, 207a, and 207b, respectively, which are connected to DC voltage source 120 and RF source 130 (e.g., an RF voltage source) via connection lines 206a, 206b and connection pads 132a, 132b, 134a, and 134b on the body of chamber 155 of OFIS device 100. Filtering segment 104 is connected to detection segment 106 via interface 114.

[0040]

[46] Filtering segment 104 has a width W2 that, in some embodiments, is about 0.13 cm to about 0.38 cm (about 0.05 inches to about 0.15 inches), and in other embodiments, is about 0.19 cm to about 0.30 cm (about 0.075 inches to about 0.12 inches). In some embodiments, the width of filtering segment W2 is the same as the width W1 of ionization segment channel 228, and in other embodiments, W1 and W2 are different. In some embodiments, interface 114 has the same width as filtering segment 104. In some embodiments, due to the narrowing of transition zone 211 and interface 112, gas flow 156 enters filtering segment 104 as a jet input. In some embodiments, paired parallel filter electrodes 216A, 216B and paired parallel detector electrodes 204A, 204B are parallel to one another. In some embodiments, the transition zone 211 of the ionization segment 102 is tapered to prevent vortices and generate jet input. Jet input is facilitated by the change in height H1 of the ionization segment channel 228 relative to the height H2 of the filtration segment channel 230 (see FIG. 2B). In some embodiments, the channel height is reduced by 5× to 7× when transitioning from the ionization segment 102 to the filtration segment 104, while the channel width remains constant. In some embodiments, the change in height of the ionization segment channel 228 relative to the filtration segment channel 230 is a step-down change rather than a gradual change.

[0041]

[47] The detection segment 106 is also shown in FIG. 2A. As discussed herein, the detection segment 106 has two parallel electrodes. FIG. 2A shows the top detector electrode 204A parallel to the bottom detector electrode 204B (shown in FIG. 2B) disposed therebelow. The top and bottom detector electrodes 204A, 204B are connected to connection lines 184a, 184b that connect to the detection system 140 via connection line 212 and connection pads 144a, 144b on the body of the chamber 155 of the OFIS device 100, and the detection system 140 is connected to the voltage source 120 via two or more electrical connections 192a, 192b. In some embodiments, two ion-guiding electrodes 265A, 265B are disposed parallel to each other on opposite sidewalls of the detection segment 106. The ion-guiding electrodes 265A, 265B surround the detector electrodes 204A, 204B. In some embodiments, the ion-guiding electrodes 265A, 265B are connected to the DC voltage source 120 via two or more connecting wires 188a, 188b.

[0042]

[48] ​​In some embodiments, the detection segment 106 has a width W4. In some embodiments, the width W4 of the detection segment 106 is the same as the width W2 of the filtration segment 104, while in other embodiments the widths are different. In some embodiments, the width W2 of the filtration segment 104 and the width W4 of the detection segment 106 are 1 / 2 the width W1 of the ionization segment 102.

[0043]

[49] In some embodiments, the combined length of the filtering segment 104 and the sensing segment 106 ranges from about 0.6 inches to about 0.75 inches (1.52 cm to about 1.60 cm). The sensing segment 106 includes an opening 142 and ground shields 220A, 220B on the exterior surface of the OFIS device 100. The top ground shield 220A is parallel to the bottom ground shield 220B (as shown in FIG. 2B). The top and bottom ground shields 220A, 220B are connected to one or more connection wires 121 that are connected to a voltage source 120 via connection pads 240a, 240b on the body of the chamber 155 of the OFIS device 100. In some embodiments, the top and bottom ground shields 220A, 220B are connected to ground. 2A and 2D . In some embodiments, the body of the chamber 155 of the OFIS device 100 has an indentation 202 to indicate the orientation of the segment of the replaceable OFIS device 100 within the system 110. In some embodiments, the indentation 202 defines the orientation of the body of the chamber 155 when replacing the integrated OFIS device 100.

[0044] 2B is a schematic cross-sectional view 250 of the integrated OFIS device 100 of FIG. 2A along line BB, showing the ionization segment 102, the filtration segment 104, and the detection segment 106. As shown, the ionization segment 102 includes a first aperture 124, a second aperture 126, and an observation window 213 disposed above the ionization zone 210 of the ionization segment 102. The ionization segment 102 is connected to the filtration segment 104 via an interface 112. In some embodiments, the height H1 of the ionization segment 102 ranges from about 0.1 cm to about 0.63 cm (about 0.04 inches to about 0.25 inches), and in other embodiments, the height H1 ranges from about 0.2 cm to about 0.51 cm (about 0.08 inches to about 0.2 inches). As shown in FIG. 2B, the filtration segment 104 has two parallel electrodes 216A, 216B, which are the top and bottom of the filtration segment 104, respectively. Filtration segment 104 is connected to detection segment 106 via interface 114. In some embodiments, filtration segment 104 has a height H2 that ranges from about 0.04 cm to about 0.09 cm (about 0.015 inches to about 0.035 inches), and in other embodiments, height H2 is from about 0.05 cm to about 0.07 cm (about 0.02 inches to about 0.027 inches). In some embodiments, the heights of interface 112 and interface 114 are the same as height H2 of filtration segment 104.

[0045] 2B also shows the detection segment 106. As discussed herein, the detection segment 106 has two parallel detector electrodes 204A, 204B. As shown, the top detector electrode 204A is parallel to the bottom detector electrode 204B. In some embodiments, the detection segment 106 has a height H3 ranging from about 0.10 cm to about 0.51 cm (about 0.04 inches to about 0.2 inches), and in other embodiments, H3 is from about 0.2 cm to about 0.25 cm (about 0.08 inches to about 0.1 inches). In some embodiments, the height H3 is the same as the height H1. The detection segment 106 includes an opening 142 and a ground shield 220A on the outer surface of the OFIS device 100 and a ground shield 220B on the bottom surface of the OFIS device 100. A gas flow 156 passes through a filtration segment channel 230 between the top electrode 216A and the bottom electrode 216B. The gas flow 158 then passes through the detection segment channel 232 between the top detector electrode 204A and the bottom detector electrode 204B of the detection segment. In some embodiments, the ionization segment channel 228, the filtration segment channel 230, and the detection segment channel 232 are segments of a single continuous channel.

[0046]

[52] In some embodiments, the height H1 of the ionization segment channel 228 and the height H3 of the detection segment channel 232 are greater than the height H2 of the filtration segment channel 230. In some embodiments, the height H1 of the ionization segment channel 228 is the same as or greater than the height H3 of the detection segment channel 232. In some embodiments, the height H1 of the ionization segment channel 228 is about 5x to about 7x the height H2 of the filtration segment channel 230. In some embodiments, the height H3 of the detection segment channel 232 is about 1x to about 5x the height H2 of the filtration segment channel. In some embodiments, the height H1 of the ionization segment channel 228 is approximately the same as the height H3 of the detection segment channel 232. In some embodiments, the widths of the ionization segment channel 228, the filtration segment channel 230, and the detection segment channel 232 are approximately the same. In some embodiments, the change in height of the detection segment channel 232 from the filtration segment channel 230 is a step-up change rather than a gradual change. The stepped channel geometry between the filter and detection segments allows the detector electrodes 204A, 204B and ion-guiding electrodes 265A, 265B to reside closer to the filter electrodes 216A, 216B, reducing ion losses due to exposed dielectric surfaces as well as the potential for voltage leakage. Thus, the stepped channel geometry provides higher ion transmission efficiency.

[0047]

[53] Figure 2C is a schematic cross-sectional view 260 of the integrated OFIS device 100 taken along line CC in Figure 2A through the filtration segment 104. Figure 2C shows a cross-section 107 of the filtration segment 104 having an inner surface 105 surrounding a filtration segment channel 230. In some embodiments, the material of the body of the chamber 155 includes one or more of, but is not limited to, alumina, ceramic, LCP, PEEK, low temperature co-fired ceramic (LTCC), or silicon or other semiconductor materials. As shown, top and bottom filter electrodes 216A, 216B are disposed on opposing walls of the filtration segment channel 230. Surface heaters 225A, 225B are mounted on and connected to the exterior surface of the chamber 155. Power is supplied to the surface heaters 225A and 225B via connection pads 172a, 172b on the exterior surface of the body of the chamber 155 of the OFIS device 100. Surface heaters 225A and 225B are used to heat ionization segment channel 228, filtration segment channel 230, and detection segment channel 232. In some embodiments, the temperature inside the chamber is set within a predetermined range of about ambient temperature to about 200°C. As shown, a temperature sensor 222, such as a thermistor, is mounted on OFIS device 100, and the sensor is connected to control system 180 via control line 119 to measure the temperature of OFIS device 100. Based on the measured temperature, control system 180 regulates the temperature within the predetermined range via feedback control. In some embodiments, the thermistor 222 is connected to connection pad 245. As shown, ground shields 220A, 220B extend parallel to the length of detector electrodes 204A, 204B. In some embodiments, the surface heaters 225A, 225B do not overlap the ground shields 220A, 220B, but are positioned in front of and behind the ground shields 220A, 220B and extend toward the opening 142. In some embodiments, the control system 180 also controls the ground shields 220A, 220B.

[0048]

[54] Figures 2D and 2E show a schematic plan view and a cross-sectional view along line DD, respectively, of a two-segment integrated OFIS device 103 according to one embodiment of the present disclosure. Figure 2D shows a plan view 201 of the integrated OFIS device or sensor 103 of Figure 1B, showing the filtering segment 104 and the sensing segment 106.

[0049]

[55] Carrier gas and material vapor flow from the ionization device 102 through the inlet 112 to the filtering segment 104. As discussed herein, the filtering segment 104 has two parallel filter electrodes 216A, 216B. FIG. 2D shows the top electrode 216A parallel to the bottom electrode 216B (shown in FIG. 2E) disposed below it. The top and bottom electrodes 216A, 216B are connected to connection lines 197a, 197b, 207a, 207b, which are connected to the voltage source 120 and the RF voltage source 130, respectively, via connection lines 206a, 206b and connection pads 132a, 132b, 134a, 134b on the body of the chamber 155 of the OFIS device 103. The filtering segment 104 is connected to the detection segment 106 through an interface 114. The filtering segment 104 and the detection segment 106 have widths W2, W4 in the same range as those disclosed herein with reference to the three-segment OFIS device 100. In some embodiments, the interface 114 has a width the same as that of the filtering segment 104. In some embodiments, there is a narrowing of the transition zone between the ionizing device 102 and the inlet 112 so that the gas flow entering the filtering segment 104 enters as a jet input. In some embodiments, the pair of parallel filter electrodes 216A, 216B and the pair of parallel detector electrodes 204A, 204B are parallel to one another.

[0050]

[56] As discussed herein, the detection segment 106 has two parallel detector electrodes 204A, 204B. Figure 2D shows the top detector electrode 204A parallel to the bottom detector electrode 204B (shown in Figure 2E) located below it. The top and bottom detector electrodes 204A, 204B are connected to connection lines 184a, 184b via connection line 212 and connection pads 144a, 144b on the body of the chamber 155 of the OFIS device 103, which are connected to the detection system 140 via connection lines 192a, 192b to the voltage source 120. The detection segment 106 includes an opening 142 and ground shields 220A, 220B on the outer surface of the OFIS device 103. The top ground shield 220A is parallel to the bottom ground shield 220B (shown in Figure 2E). The top and bottom grounded shields 220A, 220B are connected to connection pads 240a, 240b on the body of the chamber 155 of the OFIS device 103 via connection wires 121 that are connected to the voltage source 120. In some embodiments, the top and bottom grounded shields 220A, 220B are connected to ground. In some embodiments, two ion-guiding electrodes 265A, 265B are positioned parallel to each other on opposite sidewalls of the detection segment 106. The ion-guiding electrodes 265A, 265B surround the detector electrodes 204A, 204B. In some embodiments, the ion-guiding electrodes 265A, 265B are connected to the DC voltage source 120 via two or more connection wires 188a, 188b. In some embodiments, DC voltage source 120 includes multiple DC voltage sources (e.g., a first DC voltage source, a second DC voltage source, a third DC voltage source, etc.), where each DC voltage source provides a DC voltage to a different pair of opposing electrodes (e.g., filter electrodes 216A, 216B, detector electrodes 204A, 204B, ion-guiding electrodes 265A, 265B, and ground shields 220A, 220B). Ion-guiding electrodes 265A, 265B increase the efficiency of detection segment 106 by directing material vapor ions toward detector electrodes 204A, 204B. Ion-guiding electrodes 265A, 265B also prevent leakage current from filtering segment 104 from affecting detector electrodes 204A, 204B.

[0051]

[57] In some embodiments, the body of the chamber 155 of the OFIS device 103 has a recess 202 that defines the orientation of the OFIS device 103 when replacing the integrated OFIS device 103 in the OFIS system 113.

[0052]

[58] Figure 2E is a schematic cross-sectional view 251 along the length of the integrated OFIS device 103 of Figure 2D along line DD, showing the filtering segment 104 and the sensing segment 106. As shown in Figure 2E, the filtering segment 104 has two parallel electrodes 216A and 216B at the top and bottom of the filtering segment 104, respectively. The filtering segment 104 is connected to the sensing segment 106 via interface 114. The heights H2, H3 of the filtering and sensing segments are the same as the corresponding heights of the three-segment integrated OFIS device 100 discussed herein.

[0053]

[59] Gas flow 156 passes through a filtration segment channel 230 between top electrode 216A and bottom electrode 216B. Gas flow 158 then passes through a detection segment channel 232 between top detector electrode 204A and top ion guiding electrode 265A and bottom detector electrode 204B and bottom ion guiding electrode 265B.

[0054]

[60] In some embodiments, the detection segment 106 has the same width as the filtration segment 104. In some embodiments, the width W2 of the filtration segment 104 and the width W4 of the detection segment 106 are half the width W1 of the ionization segment 102. The stepped channel geometry between the filter and detection segments allows the detector electrodes 204A, 204B and the ion-guiding electrodes 265A, 265B to reside closer to the filter electrodes 216A, 216B, reducing ion loss due to exposed dielectric surfaces as well as the potential for voltage leakage.

[0055]

[61] Figure 2F shows a cross-sectional view of an OFIS device illustrating the motion of each ion according to an embodiment of the present disclosure. Figure 2F is a schematic cross-sectional view 290 of the integrated OFIS device 100 of Figure 2A along line BB or the two-segment OFIS device 103 along line DD of Figure 2D. It is understood that the two-segment OFIS device 103 does not include an integrated ionization segment. In the case of a three-segment OFIS device 100, the ionization segment 102 is part of the OFIS device 100. In the case of a two-segment OFIS device 103, the ionization segment 102 is a separate component of the OFIS system 113. The carrier gas flow 152 and the material vapor flow 154 are mixed within the ionization segment 102 and pass through the ionization tool 125. The ionization tool 125 generates positive ions 218 and negative ions 217 and generates a gas flow 156 that passes through the filtering segment channel 230. Thus, the gas flow 156 contains positive ions 218, negative ions 217 and neutral atoms / molecules.

[0056]

[62] During operation, DC voltages are applied to the ionization region electrodes 255A, 255B within the ionization region. In some embodiments, a negative DC voltage −VDC1a is applied to the top electrode 255A and a positive DC voltage +VDC1b is applied to the bottom electrode 255B by voltage source 120. In other embodiments, a positive voltage is applied to the top electrode 255A and a negative voltage is applied to the bottom electrode 255B. In some embodiments, the applied voltages +VDC1a and −VDC1b range from about −20 V to about +20 V, while in other embodiments, the applied voltages range from about −10 V to about 10 V. Figure 2F illustrates a jet input embodiment, as indicated by a narrow opening at the interface 112 between the ionization segment 102 and the filtration segment 104.

[0057]

[63] During operation, a DC voltage is applied to the parallel filter electrodes 216A, 216B in the filtration segment. In some embodiments, a negative DC voltage -VDC2a is applied to the top electrode 216A and a positive DC voltage +VDC2b is applied to the bottom electrode 216B by voltage source 120. In other embodiments, a positive voltage is applied to the top electrode 216A and a negative voltage is applied to the bottom electrode 216B. In addition, an RF voltage VRF, as described with reference to FIG. 1C, is applied between the top and bottom electrodes 216A, 216B. As shown in FIG. 2F, the combination of the DC and RF voltages discharges some of the ions by contacting the electrodes 216A, 216B in the filter zone 104, and some negative and positive ions exit the filtration segment 104 and enter the detection segment 106. Although one ion is shown in contact with each of detector electrodes 204A, 204B, in some embodiments, multiple ions contact detector electrodes 204A, 204B. In some embodiments, the applied voltages +VDC2a and -VDC2b range from about -45V to about +20V, while in other embodiments, the applied voltages range from about -40V to about +15V.

[0058]

[64] During operation, in some embodiments, voltage source 120 applies a negative DC voltage -VDC3a to top detector electrode 204A and a positive DC voltage +VDC3b to bottom detector electrode 204B. In other embodiments, a positive voltage is applied to top electrode 204A and a negative voltage is applied to bottom electrode 204B. The application of voltages -VDC3a and +VDC3b causes positive and negative ions to be discharged (e.g., detected) by top and bottom detector electrodes 204A and 204B, respectively. As shown, the discharged ions leave the detection segment as part of exhaust gas flow 160 through opening 142. In some embodiments, the voltages applied to detector electrodes 204A, 204B range from about −20 volts to about +20 volts and detector electrodes 204A, 204B have opposite polarities, while in other embodiments, voltages −VDC3a and +VDC3b range from about −10 V to about +10 V. During operation, DC voltages are applied to ion guiding electrodes 265A, 265B to guide ions toward detector electrodes 204A, 204B. In some embodiments, a negative DC voltage −VDC4a is applied to top ion guiding electrode 265A and a positive DC voltage +VDC4b is applied to bottom ion guiding electrode 265B by voltage source 120. In other embodiments, a positive voltage is applied to top electrode 265A and a negative voltage is applied to bottom electrode 265B. In some embodiments, the applied voltages +VDC4a and -VDC4b range from about -20 V to about +20 V, while in other embodiments, the applied voltages range from about -10 V to about 10 V. In some embodiments, the voltages applied to the top ion conducting electrode 265A and the bottom ion conducting electrode 265B are approximately the same as the voltages applied to the corresponding top and bottom detector electrodes 204A, 204B. In some embodiments, VDC2a or -VDC3a ranges from about -3 volts to about -15 volts, and +VDC2b or +VDC3b ranges from about 3 volts to about 15 volts. In other embodiments, -VDC2a or -VDC3a ranges from about -4.7 volts to about -12.5 volts, and +VDC2a or +VDC3a ranges from about 4.7 volts to about 12.5 volts.In some embodiments, −VDC2a is applied to the top electrode 216A and +VDC2b is applied to the bottom electrode 216B, while +VDC3a is applied to the top detector electrode 204A and −VDC3a is applied to the bottom detector electrode 204B. In some embodiments, +VDC2b is applied to the top electrode 216A and −VDC2a is applied to the bottom electrode 216B, while +VDC3b is applied to the top detector electrode 204A and −VDC3a is applied to the bottom detector electrode 204B. In some embodiments, 0V is applied to the top electrode 216A or the bottom electrode 216B, and a positive or negative voltage is applied to the other electrode.

[0059]

[65] In some embodiments, the flow of ions depends on the charge of the ions, the mobility of the ions, and the voltages applied to the top and bottom electrodes 216A, 216B. In some embodiments, the ion flow is programmed and controlled by the control system 180. In some embodiments, a higher flow rate may provide higher sensitivity, and a higher DC voltage applied to the filter electrodes 216A, 216B may provide improved ion filtration.

[0060] 3A, 3B, 3C, 3D, and 3E show embodiments of integrated OFIS devices according to the present disclosure. FIG. 3A shows a three-segment integrated OFIS device 100. The body of the integrated OFIS device 100 in FIG. 3A corresponds to the chamber 155 in FIG. 1A and includes an ionization segment 102, a filtration segment 104 connected to the ionization segment 102 via an interface 112, and a detection segment 106 connected to the filtration segment 104 via an interface 114. The difference is that FIG. 3A includes a mixer 305 within the ionization segment 102 so that the carrier gas stream 152, the material vapor stream 154, and the modifying gas 190 are mixed in the mixer 305, and then the mixture is ionized. As shown in Figures 3B and 3C, in some embodiments, mixer 305 is external to integrated OFIS device 100, and the mixture is transferred to ionization segment 102 via interface 302 and stream 111. In some embodiments, stream 111 is the sum of carrier gas stream 152, material vapor stream 154, and modifying gas 191. Figure 3B corresponds to Figure 3A, except that mixer 305 and interface 302 are external to ionization segment 102 but are not in the same line as ionization segment 102, filtration segment 104, and detection segment 106. Figure 3C corresponds to Figure 3B, except that mixer 305 is in the same line as ionization segment 102, filtration segment 104, and detection segment 106.

[0061]

[67] Figure 3D corresponds to Figure 3B, except that the ionization segment 102 is positioned outside the two-segment integrated OFIS device 103, and is similar to Figure 3B, except that the mixer 305 and interface 302 are not in the same line as the ionization segment 102, the filtration segment 104, and the detection segment 106. Figure 3E corresponds to Figure 3C, except that the ionization segment 102 is positioned outside the two-segment integrated OFIS device 103, and the interface 302 is in a linear arrangement with the ionization segment 102, the filtration segment 104, and the detection segment 106.

[0062] 4 shows a flow diagram of a process 400 for operating an OFIS device according to some embodiments of the present disclosure. In some embodiments, as shown in FIGS. 1A and 1B, in operation S410, a mixture of a carrier gas and a material vapor is flowed by the carrier gas through the ionization zone 210 of the ionization tool 125 of the ionization segment 102. In operation S420, at least a portion of the material vapor is ionized to produce ions of the material vapor in the mixture. A DC voltage or ground is applied to the ionization region electrodes 255A, 255B to prevent charging of the dielectric surfaces in the ionization segment 102. In operation S430, the mixture is flowed by the carrier gas from the ionization segment 102 to the filtering segment 104. In operation S440, the ions in the mixture are filtered by simultaneously applying an RF oscillating voltage VRF and DC voltages of opposite polarity +VDC1 / −VDC1 to two parallel filter electrodes 216A, 216B on opposite walls of the filtering segment 104. In operation S450, the mixture flows with the carrier gas from the filtration segment 104 to the detection segment 106. In operation S460, ions are guided by applying a DC voltage to the ion guide electrodes 265A, 265B surrounding the detector electrodes. The guided ions are detected by applying a DC voltage to two parallel detector electrodes 204A, 204B on opposite walls of the detection segment.

[0063]

[69] In some embodiments, in operation S410, the material vapor is a vapor of a predetermined material. In some embodiments, the material vapor flows intermittently through the OFIS device. In some embodiments, the material vapor is initiated by a person's breath.

[0064] 5A, 5B, and 5C illustrate an ionization segment of an integrated OFIS device according to an embodiment of the present disclosure. FIGS. 5A, 5B, and 5C illustrate the ionization segment 102 and the ionization zone 210 within the ionization segment 102. In FIG. 5A, the carrier gas flow 152, the material vapor flow 154, and the modifier gas flow 191 enter the ionization segment 102 and mix, and then the mixture is ionized in the ionization zone 210. Thus, the carrier gas flow, the material vapor, and the modifier gas may be ionized together. In FIG. 5B, the carrier gas flow 152 and the modifier gas flow 191 enter the ionization segment 102 and mix, and then the mixture is ionized in the ionization zone 210. Continuing further, the material vapor flow 154 enters the ionization segment 102 and is ionized by the ionized carrier gas and / or modifier gas. FIG. 5C is similar to FIG. 5B except that the reformulated gas flow 191 enters before the carrier gas flow 152, while in FIG. 5C the material vapor flow 154 also enters the ionization segment 102 and is ionized by the ionized carrier gas.

[0065] In some embodiments, the three-segment OFIS device 100 includes one or more inlet ports 124, 126, 182, ionization segment 102, filtration segment 104, detector segment 106, and exhaust port 142, all connected by a single channel. All of these components are contained within a single device with the shield, ground shield 220A, 220B, heater 225A, 225B, temperature sensor 222, and electrical connection pads 122a, 122b, 132a, 132b, 134a, 134b, 144a, 144b, 145a, 145b, 172a, 172b, 219a, 219b, 240a, 240b, 245 on its exterior. Ionization region electrodes 255A, 255B, filter electrodes 216A, 216B, detector electrodes 204A, 204B, and ion guide electrodes 265A, 265B in a single in-line channel provide shielding, RF voltage, DC voltage, and ion count measurements in various segments.

[0066]

[72] In some embodiments of the three-segment OFIS device 100, mixing occurs within the device or external to the device. The ionization segment may include a single inlet or multiple inlets, which may include a material vapor inlet 126, a carrier gas inlet 124, and a modifying gas inlet 182 in various introduction orders, and which may be in-line or angled relative to the channel. The ionization segment 102 may include parallel ionization region electrodes 255A, 255B attached to a DC voltage source 120 or ground, an ionization observation window 213, electrical connections to the exterior of the device, and an ionization tool 125.

[0067]

[73] The ionization tool 125 may be integrated between the inlet ports 124, 126, 182 or after the inlet ports 124, 126, 182. In some embodiments, non-radioactive ionization is used. Non-radioactive ionization includes, but is not limited to, capacitive discharge ionization (plasma), UV ionization, and electrospray ionization. In other embodiments, radioactive ionization is used. In some embodiments, a single ionization source 125 is used. In other embodiments, multiple different ionization sources may be used.

[0068]

[74] In some embodiments of the three-segment OFIS device 100, there is a channel constraint in the transition zone 211 between the ionization segment 102 and the filtering segment 104 to funnel ions into the filtering segment 102, thereby providing a jet effect and increasing ion flow velocity. In some embodiments, the channel dimensions of the filtering segment 104 are different from those of the ionization segment 102. The filtering segment 104 also includes a pair of filter electrodes 216A, 216B on opposite sides of the channel 230. In some embodiments, in applying RF and DC voltages, opposite polarities are shared between the electrodes and summed into a total voltage (e.g., all voltages may be applied to one electrode and 0V may be applied to the other electrode). In some embodiments, several DC voltages are applied singly in discrete steps, in a full range scan, in a partial range scan, or in multiple partial range scans. The filtering segment 104 includes electrical connections to the exterior of the device.

[0069]

[75] In some embodiments of the three-segment OFIS device 100, the detection segment 106 includes a pair of detector electrodes 204A, 204B on opposite sides of the channel 232 and a pair of ion-guiding electrodes 265A, 265B surrounding the detector electrodes 204A, 204B. The polarity of the shield and offset voltages may be matched or opposite to the filter electrodes on each side. The shield and offset voltages may be constant or variable. The detection segment 106 may include an in-line exhaust outlet 142 or an angled exhaust outlet relative to the channel 232. The detection segment 106 may further include electrical connection pads on the exterior surface of the device. In some embodiments, the channel 232 dimensions of the detection segment 106 differ from the channel 230 dimensions of the filtration segment 104.

[0070]

[76] In some embodiments, the two-segment OFIS device 103 includes one or more inlet ports 112, filtration segments 104, detector segments 106, and exhaust ports 142, all connected by a single channel 230, 232. All components are contained within a single device with shield grounds 220A, 220B, heaters 225A, 225B, temperature sensors 222, and electrical connection pads 132a, 132b, 134a, 134b, 144a, 144b, 145a, 145b, 172a, 172b, 240a, 240b, 245 on the exterior. Parallel filter electrodes 216A, 216B, detector electrodes 204A, 204B, and ion guiding electrodes 265A, 265B in a single in-line channel provide shielding, RF voltage, DC voltage, and ion count measurements within the various segments. In some embodiments, the two-segment OFIS device 103 is paired with an external mixing / ionization device 305 / 102 during operation.

[0071]

[77] In some embodiments of the two-segment OFIS device 103, a channel constraint exists in the transition zone between the external ionizing device 102 and the filtering segment 104 to funnel ions into the filtering segment 104, thereby providing a jet effect. In some embodiments, the filtering segment 104 includes a single inlet port 112 from the ionizing device 102. In some embodiments, RF and DC voltages are applied with opposite polarities split between the filter electrodes 216A, 216B and summed to a total voltage (e.g., all voltages may be applied to one electrode and 0V may be applied to the other electrode). In some embodiments, the DC voltage is applied alone in discrete steps, full range scans, partial range scans, or multiple partial range scans. The filtering segment 104 includes electrical connections to the exterior of the device.

[0072]

[78] In some embodiments of the two-segment OFIS device 103, the polarity of the shield and offset voltages may be matched to the filter electrodes 216A, 216B on each side. The shield and offset voltages may be constant or variable. The detection segment 106 may include an in-line exhaust outlet 142 or an exhaust outlet angled relative to the channel. The detection segment 106 also includes an electrical connection to the exterior surface of the device. In some embodiments, the channel dimensions of the detection segment are different from those of the filtration segment.

[0073]

[79] In some embodiments, the two-segment OFIS device 103 or the three-segment OFIS device 100 is a replaceable disposable part of the OFIS system 110, 113. When the sensitivity of the OFIS device 100, 103 falls below a threshold, the OFIS device 100, 103 can be easily removed from the OFIS system 110, 113 and replaced with a replacement OFIS device 100, 103. Alternatively, in some embodiments, the ionizing device 102 used with the two-segment OFIS device 103 is a replaceable part.

[0074]

[80] In the above embodiments, because ionization occurs internally within the integrated OFIS device and can be achieved by a non-radioactive method of generating a plasma region, the integrated OFIS device is safe and therefore not subject to radioactive source regulations and inspections. In some embodiments, the non-radioactive source can include redundancy to extend the usable life of wear elements. Additionally, if the OFIS device fails, for example if it fails calibration, the integrated OFIS device can be easily and quickly replaced, and therefore no alignment is required.

[0075] 6 shows a flow chart of a method of operating an OFIS system according to some embodiments of the present disclosure. In operation S610, a mixture of carrier gas and material vapor is flowed through the filtration segment 104 and the detection segment 106 by the carrier gas. In operation S620, at least a portion of the material vapor is ionized in the ionization zone of the ionization segment 102 to produce material vapor ions in the mixture. Next, in operation S630, a first DC voltage or ground is applied to two parallel ionization region electrodes 255A, 255B on opposite walls of the ionization segment. In operation S640, at least a portion of the ions in the mixture other than the material vapor ions are filtered by simultaneously applying an RF oscillating voltage and a second DC voltage of opposite polarity to two parallel filter electrodes 216A, 216B on opposite walls of the filtration segment 104. In operation S650, the material vapor ions are then detected by applying a third DC voltage to two parallel detector electrodes 204A, 204B on opposite walls of the detection segment 106 and by applying a fourth DC voltage to two parallel ion-guiding electrodes 265A, 265B, the two parallel ion-guiding electrodes 265A, 265B surrounding the two parallel detector electrodes 204A, 204B. In some embodiments, in operation S660, a carrier gas is provided from the carrier gas source 116 through the first opening 124 of the ionization segment 102, the carrier gas flows the material vapor into the ionization zone; and a modifying gas is provided to the ionization segment 102 through the second opening 182. In some embodiments, in operation S670, the carrier gas and the material vapor are mixed within the ionization segment 102. In operation S670, the positive and negative ions are separated, in some embodiments, by simultaneously applying an RF oscillating voltage and a second DC voltage to two parallel filter electrodes 216A, 216B on opposite walls of the filtering segment 104. In some embodiments, in operation S680, the integrated oscillating field ion spectroscopy device is removed from the system when the sensitivity of the device falls below a threshold; and a replacement integrated oscillating field ion spectroscopy device is installed in the system.

[0076] 7 shows a flow chart of a method of operating an OFIS system according to some embodiments of the present disclosure. In operation S710, a mixture of carrier gas and material vapor ions is flowed by the carrier gas through the filtration segment 104 and the detection segment. In operation S720, at least a portion of ions other than the material vapor ions in the mixture are filtered by simultaneously applying an RF oscillation voltage and a first DC voltage of opposite polarity to two parallel filter electrodes 216A, 216B on opposing walls of the filtration segment 104. Next, in operation S730, the material vapor ions are detected by applying a second DC voltage to two parallel detector electrodes 204A, 204B on opposing walls of the detection segment 106 and a third DC voltage to two parallel ion-guiding electrodes 265A, 265B on opposing walls of the detection segment 106, the ion-guiding electrodes 265A, 265B surrounding the detector electrodes 204A, 204B. In some embodiments, in operation S740, a modifying gas is provided to the mixture of carrier gas and material vapor ions. In some embodiments, in operation S740, positive and negative ions are separated by simultaneously applying an RF oscillating voltage and a first DC voltage to two parallel filter electrodes 216A, 216B on opposite walls of the filtering segment 104. In some embodiments, in operation S750, the integrated oscillating field ion spectroscopy device 103 is removed from the system when its sensitivity falls below a threshold; and a replacement integrated oscillating field ion spectroscopy device is installed in the system.

[0077]

[83] Some embodiments of the present disclosure include a method for calibrating an integrated oscillating-field ion spectroscopy device having a single-channel chamber divided into three segments, including an ionization segment 102, a filtering segment 104, and a detection segment 106, arranged in sequence. The filtering segment 104 is located downstream of the ionization segment 102 in a flow direction of a carrier gas. The detection segment 106 is located downstream of the filtering segment 104 in a flow direction of the carrier gas. The method includes flowing a mixture of a carrier gas and a predetermined amount of a calibration material with the carrier gas through an ionization zone of an ionization tool 125 of the ionization segment 102, and ionizing the calibration material to produce calibration material ions in the mixture. The mixture is flowed by the carrier gas from the ionization segment to the filtering segment 104, and at least a portion of the ions in the mixture, other than the calibration material ions, are filtered by simultaneously applying an RF oscillating voltage and a first DC voltage of opposite polarity to two parallel electrodes 216A, 216B on opposing walls of the filtering segment 104. The mixture is swept by a carrier gas from the filtration segment 104 to the detection segment 106, and the calibration material ions are detected by applying a second DC voltage to two parallel electrodes 204A, 204B on opposing walls of the detection segment 106 to discharge the calibration material ions. The amount of calibration material discharged is determined, and calibration is successful if the amount of calibration material discharged exceeds a predetermined threshold amount of calibration material. In some embodiments, the OFIS device is calibrated with a material that is chemically similar or identical to the material vapor that will subsequently be detected. In some embodiments, calibration occurs as a separate cycle without the material vapor. In some embodiments, calibration occurs as part of an analysis cycle with the material vapor.

[0078]

[84] In some embodiments, the RF oscillation voltage and a first DC voltage are applied to two parallel electrodes 216A, 216B on opposing walls of the filtering segment 104, and a second DC voltage is applied to two parallel detector electrodes 204A, 204B on opposing walls of the detection segment 106. In some embodiments, the threshold amount is greater than or equal to about 90% of the predetermined amount of calibration material. If adjusting the parameters does not result in a successful calibration, in some embodiments, a signal is generated by the control system 180 of the OFIS system 110 that the integrated OFIS device 100 requires replacement. In some embodiments, the three-segment OFIS device 100 is disposable. The three-segment OFIS device 100 can be removed from the OFIS system and replaced with a replacement three-segment OFIS device.

[0079]

[85] In some embodiments, results from the calibration material are registered, and the detection algorithm may dynamically modify the material vapor measurement. For example (using arbitrary numbers as an example), if the calibration material normally measures 100 in a properly functioning system, and the material vapor normally measures 50 in this properly functioning system, and the calibration alone measures 90, indicating that system sensitivity has degraded, the material vapor will also show a reduced value. In this case, the algorithm may boost the measurement based on the calibration material's degraded measurement, so the system can continue to function with uniform and consistent sensitivity. There may also be a threshold value for the calibration material measurement (e.g., 70) that will indicate that the system sensitivity is too low and unacceptable. In this case, the system may notify the operator to replace the OFIS device or seek service.

[0080]

[86] The two-segment OFIS device 103 disclosed herein can be calibrated in a similar manner to the three-segment OFIS device 100. Similarly, the two-segment OFIS device 103 is disposable and can be removed and replaced with a replacement two-segment OFIS device. The ionization segment 102 remains part of the OFIS system 113 even when the disposable two-segment OFIS device 103 is removed and replaced.

[0081]

[87] It will be understood that not all advantages are necessarily discussed herein, that no particular advantage is required for every embodiment or example, and that other embodiments or examples may exhibit various advantages.

[0082]

[88] The foregoing outlines features of some embodiments or examples so that those skilled in the art may better appreciate the aspects of the present disclosure. Those skilled in the art should appreciate that they may readily use this disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and / or achieving the same advantages of the embodiments or examples introduced herein. Those skilled in the art should also appreciate that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that those skilled in the art may make various changes, substitutions, and alterations therein without departing from the spirit and scope of the present disclosure.

Claims

1. 1. An integrated oscillating field ion spectroscopy device comprising a chamber divided into at least three connected segments comprising an ionization segment, a filtering segment, and a detection segment arranged in sequence, wherein the filtering segment is disposed downstream of the ionization segment in a flow direction of a carrier gas, and the detection segment is disposed downstream of the filtering segment in the flow direction of the carrier gas, the ionization segment comprising: a first opening and a second opening, the carrier gas flowing through the first opening into a first channel region in the ionization segment and the material vapor flowing through the second opening into the first channel region of the ionization segment; an ionization tool mounted within the first channel region configured to ionize the material vapor; and two parallel ionization region electrodes on opposite walls of the first channel region, the two parallel ionization region electrodes connected to a first DC voltage source or ground, and the two parallel ionization region electrodes configured to prevent charging of dielectric surfaces within the ionization segment; the filtering segment: two parallel filter electrodes on opposing walls of a second channel region of the filtration segment parallel to the flow direction of the carrier gas, the two parallel filter electrodes connected to a second DC voltage source to receive a second DC voltage of opposite polarity, the two parallel filter electrodes connected to a radio frequency (RF) voltage source to receive an RF oscillating voltage in addition to the second DC voltage, the two parallel filter electrodes configured to generate an electric field by the second DC voltage and the RF oscillating voltage to filter ions passed from the ionization segment; and the detection segment: two parallel detector electrodes on opposing walls of a third channel region of the detection segment parallel to the flow direction of the carrier gas, the two parallel detector electrodes connected to a third DC voltage source to receive a third DC voltage and connected to a detection system, the two parallel detector electrodes configured to generate an electric field with the third DC voltage to attract filtered material vapor ions; and two parallel ion guiding electrodes on opposing walls of the third channel region, the ion guiding electrodes surrounding the detector electrode, the two parallel ion guiding electrodes connected to a fourth DC voltage source to receive a fourth DC voltage, and the two parallel ion guiding electrodes configured to generate an electric field to guide ions toward the two parallel detector electrodes; the detection segment is configured to count the number of positive and negative ions in the material vapor; The integrated oscillating field ion spectroscopy device, wherein the first channel region, the second channel region, and the third channel region are arranged along a line and form a single channel.

2. 10. The integrated oscillating field ion spectroscopy device of claim 1, further comprising a first interface between the ionization segment and the filtering segment, the ionization segment has a transition region adjacent the first interface, and the width of the transition region tapers from a first width to a second width, the second width being the width of the first interface, and the second width being 2 to 5 times smaller than the first width.

3. 10. The integrated oscillating field ion spectroscopy device of claim 1, further comprising one or more ground shields on an outer surface of the detection segment.

4. 10. The integrated oscillating field ion spectroscopy device of claim 1, wherein the ionization segment further comprises an observation window, the ionization zone being visible through the observation window.

5. The integrated oscillating field ion spectroscopy device of claim 1 , wherein the ionization tool comprises a plasma source.

6. 2. The integrated oscillating field ion spectroscopy device of claim 1, wherein an electric field generated by the second DC voltage of opposite polarity in the second channel region has a direction that is opposite to an electric field generated by the third DC voltage in the third channel region.

7. 2. The integrated oscillating field ion spectroscopy device of claim 1, wherein the outer wall of the chamber includes a plurality of connection pads electrically connected to each one of the two parallel ionization region electrodes, the two parallel filter electrodes, the two parallel detector electrodes, the two parallel ion guiding electrodes, and the ionization tool.

8. 2. The integrated oscillating field ion spectroscopy device of claim 1, further comprising a control system coupled to the first, second, third and fourth DC voltage sources, the RF voltage source and the detection segment, wherein the control system is configured to control the second DC voltage source to adjust the second DC voltage and to adjust the amplitude or frequency of the RF pre-oscillating voltage of the RF voltage source, and is configured to control the first DC voltage, the third DC voltage and the fourth DC voltage.

9. 9. The integrated oscillating field ion spectroscopy device of claim 8, wherein the electric field generated by the second DC voltage of opposite polarity in the second channel region has a direction that is the same as the electric field generated by the third DC voltage in the third channel region.

10. 9. The integrated oscillating field ion spectroscopy device of claim 8, wherein the ionization segment further comprises a first opening and a second opening, the carrier gas flows through the first opening into the ionization segment, and the material vapor flows through the second opening into the ionization segment.

11. 1. An oscillating field ion spectroscopy system comprising: Integrated oscillating field ion spectroscopy device; and an ionization device coupled along the gas flow to the integrated oscillating field ion spectroscopy device; In the oscillating field ion spectroscopy system, the ionization device comprises an ionization tool mounted within the ionization device, the ionization tool configured to ionize a material vapor; and two parallel ionization region electrodes on opposite walls of the ionizing device, the two parallel ionization region electrodes connected to a first DC voltage source or ground, and the two parallel ionization region electrodes configured to prevent charging of dielectric surfaces within the ionizing device; The integrated oscillating field ion spectroscopy device comprises: a chamber divided into at least two connecting segments including a filtering segment and a detection segment arranged in sequence, the detection segment being arranged after the filtering segment in a flow direction of a carrier gas, and the filtering segment being arranged downstream of the ionization device; The filtration segment comprises: two parallel filter electrodes on opposing walls of a first channel region of the filtration segment parallel to the flow direction of the carrier gas, the two parallel filter electrodes connected to a second DC voltage source to receive a second DC voltage of opposite polarity, the two parallel filter electrodes connected to a radio frequency (RF) voltage source to receive an RF oscillating voltage in addition to the second DC voltage, the two parallel filter electrodes configured to generate an electric field with the second DC voltage and the RF oscillating voltage to filter ions passed from the ionization device; and two parallel detector electrodes on opposing walls of a second channel region of the detection segment parallel to the flow direction of the carrier gas, the two parallel detector electrodes connected to a third DC voltage source to receive a third DC voltage and connected to a detection system, the two parallel detector electrodes configured to generate an electric field with the third DC voltage to attract material vapor ions or other modified ions of interest, the detection system configured to determine the number of positive and negative ions of the material vapor; and and two parallel ion guiding electrodes on opposing walls of the second channel region, the ion guiding electrodes surrounding the detector electrode, the two parallel ion guiding electrodes connected to a fourth DC voltage source to receive a fourth DC voltage, and the two parallel ion guiding electrodes configured to generate an electric field to guide ions toward the two parallel detector electrodes.

12. The oscillating field ion spectroscopy system of claim 11 , wherein the first channel region and the second channel region are arranged along a line and form a single channel.

13. 12. The oscillating field ion spectroscopy system of claim 11, wherein the electric field generated by the second DC voltage of opposite polarity in the first channel region has a direction that is opposite to the electric field generated by the third DC voltage in the second channel region.

14. 12. The oscillating field ion spectroscopy system of claim 11 , wherein the outer wall of the chamber includes a plurality of connection pads electrically connected to each one of the two parallel ionization region electrodes, the two parallel filter electrodes, the two parallel detector electrodes, and the two parallel ion guiding electrodes.

15. The oscillating field ion spectroscopy system of claim 11 , wherein the integrated oscillating field ion spectroscopy device is a replaceable component of the oscillating field ion spectroscopy system.

16. The oscillating field ion spectroscopy system of claim 11 further comprising one or more shield grounds disposed on an outer surface of the detection segment.

17. 12. The oscillating field ion spectroscopy system of claim 11, further comprising a control system coupled to the second, third, and fourth DC voltage sources, the RF voltage source, and the detection segment, wherein the control system is configured to control the second DC voltage source to adjust the second DC voltage and to adjust the amplitude or frequency of the RF oscillating voltage of the RF voltage source, and to control the second DC voltage, the third DC voltage, and the fourth DC voltage.

18. 1. An integrated oscillating field ion spectroscopy device comprising a chamber divided into at least two connecting segments comprising a filtration segment and a detection segment, the detection segment being disposed downstream of the filtration segment in a flow direction of a carrier gas, the filtration segment comprising: two parallel filter electrodes on opposing walls of a filtration segment channel region parallel to a flow direction of the carrier gas, the two parallel filter electrodes being connected to a first DC voltage source to receive a first DC voltage of opposite polarity and to an RF voltage source to receive an RF oscillating voltage; The detection segment comprises: two parallel detector electrodes on opposing walls of a detection segment channel region parallel to the flow direction of the carrier gas, the two parallel detector electrodes being connected to a second DC voltage source to receive a second DC voltage, the detection segment being configured to determine a number of positive and negative ions of a material vapor; and an integrated oscillating field ion spectroscopy device comprising: two parallel ion guiding electrodes on opposing walls of the detection segment channel region, the ion guiding electrodes surrounding the detector electrode, the two parallel ion guiding electrodes connected to a third DC voltage source to receive a third DC voltage, and the two parallel ion guiding electrodes configured to generate an electric field to guide ions toward the two parallel detector electrodes.

19. 20. The integrated oscillating field ion spectroscopy device of claim 18, further comprising an ionization segment upstream of the filtering segment along the flow direction of the carrier gas, the ionization segment comprising: one or more entrances; ionization segment channel region; an ionization source within the ionization segment channel region selected from the group consisting of a cross-wire capacitive discharge ionizer, an ultraviolet ionizer, an electrospray ionizer, a radioactive ionizer, and combinations thereof, the ionization source configured to ionize the material vapor; and an integrated oscillating field ion spectroscopy device comprising: two parallel ionization region electrodes on opposite walls of the ionization segment channel region, the two parallel ionization region electrodes being connected to a fourth DC voltage source or to ground, and the two parallel ionization region electrodes being configured to prevent charging of dielectric surfaces within the ionization segment;

20. 20. The integrated oscillating field ion spectroscopy device of claim 19, wherein the height of the filtration segment channel region is less than the height of the ionization segment channel region, and the height of the detection segment channel region is greater than the height of the filtration segment channel region.

21. 1. A method of operating an integrated oscillating field ion spectroscopy system including an integrated oscillating field ion spectroscopy device, the integrated oscillating field ion spectroscopy device including a chamber divided into at least three segments including an ionization segment, a filtration segment, and a detection segment arranged sequentially in a flow direction of a carrier gas, the method comprising: flowing a mixture of the carrier gas and the material vapor ions through the filtering segment and the detection segment with the carrier gas; ionizing at least a portion of the material vapor within an ionization zone of the ionization segment to produce material vapor ions in the mixture; applying a first DC voltage or ground to two parallel ionization region electrodes on opposite walls of the ionization segment; filtering at least a portion of ions other than the material vapor ions in the mixture by simultaneously applying an RF oscillating voltage and a second DC voltage of opposite polarity to two parallel filter electrodes on opposing walls of the filtering segment; and detecting the material vapor by applying a second DC voltage to two parallel detector electrodes on opposing walls of the detection segment, and applying a fourth DC voltage to two parallel ion guiding electrodes, the two parallel ion guiding electrodes surrounding the two parallel detector electrodes.

22. providing the carrier gas from a carrier gas source through a first opening in the ionization segment, the carrier gas flowing the material vapor into the ionization zone; and 22. The method of claim 21, further comprising providing a modified gas to the ionization segment through the second opening.

23. 22. The method of claim 21, further comprising mixing the carrier gas and the material vapor within the ionization segment.

24. 22. The method of claim 21 , wherein said filtering at least a portion of ions other than said material vapor ions in said mixture comprises discharging said ions other than said material vapor ions through said two parallel detector electrodes on said opposing walls of said filtering segment.

25. 22. The method of claim 21, further comprising separating positive and negative ions by simultaneously applying the RF oscillating voltage and the second DC voltage to the two parallel filter electrodes on the opposing walls of the filtering segment.

26. removing the integrated oscillating field ion spectroscopy device from the system when the sensitivity of the device falls below a threshold; and 22. The method of claim 21, further comprising installing a permutation integrated oscillating field ion spectroscopy device in the system.

27. A method of operating an integrated oscillating field ion spectroscopy system including an integrated oscillating field ion spectroscopy device, the integrated oscillating field ion spectroscopy device including a chamber divided into at least two segments including a filtering segment and a detecting segment arranged in sequence, the detecting segment being positioned after the filtering segment in a carrier gas flow direction, the method comprising: flowing a mixture of the carrier gas and the material vapor ions through the filtering segment and the detection segment with the carrier gas; filtering at least a portion of ions other than the material vapor ions in the mixture by simultaneously applying an RF oscillating voltage and a first DC voltage of opposite polarity to two parallel filter electrodes on opposing walls of the filtering segment; and detecting the material vapor ions by applying a second DC voltage to two parallel detector electrodes on opposing walls of the detection segment and by applying a third DC voltage to two parallel ion-guiding electrodes on the opposing walls of the detection segment, the ion-guiding electrodes surrounding the detector electrodes.

28. 30. The method of claim 27, further comprising providing a modifying gas to the mixture of the carrier gas and the material vapor ions.

29. 28. The method of claim 27, wherein said filtering at least a portion of ions other than said material vapor ions in said mixture comprises discharging said ions other than said material vapor ions through said two parallel filter electrodes on said opposing walls of said filtering segment.

30. 28. The method of claim 27, further comprising separating positive and negative ions by simultaneously applying the RF oscillating voltage and the first DC voltage to the two parallel filter electrodes on the opposing walls of the filtering segment.

31. removing the integrated oscillating field ion spectroscopy device from the system when the sensitivity of the device falls below a threshold; and 28. The method of claim 27, further comprising installing a permutation integrated oscillating field ion spectroscopy device in the system.

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