Abstract: An ion mobility filter is disclosed. The present invention relates to but not exclusively a field asymmetric ion spectrometry filter. For example, we describe an ion filter for filtering ions in a gas sample. The ion filter is comprised of a plurality of electrodes, a first ion channel, and a second ion channel. The first ion channel filters ions from a target chemical in the gas sample, defines a gap between a first pair of electrodes in the plurality of electrodes, and has a first ion channel gap width. The second ion channel filters ions from the target chemical in the gas sample, defines a gap between a second pair of electrodes in the plurality of electrodes, and has a second ion channel gap width. The first ion channel gap width is greater than the second ion channel gap width.

Abstract: A sensor system comprising a housing having an inlet aperture through which fluid enters the housing and a conditioning material in the housing, the conditioning material being adapted to control levels of a substance within the housing. The sensor system comprises a sensor for analysing the fluid in the housing. The sensor system comprises circulation means which is configured to alternate circulation of fluid within the housing between a sensing fluid path in which the fluid is analysed by the sensor and a second fluid path in which the fluid flow is conditioned. A method for analysing fluid in a housing using a sensor is also provided.

Abstract: We describe a method and apparatus for detecting humidity using a Field Asymmetric Ion Mobility Spectrometry (FAIMS) system. The system may comprise an ionizer for generating ions within a gas sample, wherein each ion has an associated ion mobility; an ion filter for separating the ions by applying a compensation field and a dispersion field to the generated ions; a detector for detecting an output from the ion filter; and a processor.

Abstract: The waveform generator (10) comprises a switch (13). The waveform generator (10) comprises a transformer (15) having a primary side circuit and a secondary side circuit. The primary side circuit has a first terminal arranged to be conductively coupled to a DC voltage source, and a second terminal conductively coupled to the switch (13). The waveform generator (10) further comprises a controller (11) arranged to supply a drive signal to the switch for switching the switch between on and off states. The controller (11) is arranged to adjust the frequency of the drive signal so as to control at least one of the peak voltage and the duty cycle of a waveform generated by the waveform generator (10). The frequency of the drive signal may be adjusted as the voltage level of the DC voltage source remains constant. The frequency of the drive signal may be adjusted in response to a change in the voltage level of the DC voltage source.

Abstract: The present disclosure relates to sensor systems and methods for analysing fluid samples. The sensor system comprises a housing (220) having an inlet for a fluid sample to enter the housing, an outlet for the fluid sample to exit the housing, and a fluid sample path within the housing for the fluid sample to flow between the inlet and the outlet. The sensor system also comprises an ionizer (210) which is external to the housing and which is for ionizing the fluid sample at a first location on the fluid sample path to generate sample ions, an ion mobility filter (212) which is at least partially located within the housing and which is for filtering the generated sample ions at a second location on the fluid sample path, and a detector (214) which is external to the housing and which is for detecting the sample ions which pass through the ion mobility filter at a third location on the fluid sample path.

Abstract: The present techniques relate to methods of manufacturing MEMS gas sensors, for example, an ion mobility filter which may be used as a field asymmetric ion mobility spectrometry filter. The method comprises a step of providing a support with an aperture (S300, S302) and forming electrical connections (S304) in the support. The method also comprises steps of attaching an electrode layer to the support (S306) so that the electrode layer covers the aperture and forming a plurality of ion mobility electrodes (S308) by mechanically dicing through the electrode layer. Each adjacent pair of electrodes defines an ion channel between them and each electrode is separate from the adjacent electrode(s).

Abstract: A waveform generator configured to generate two waveforms of opposite polarity so as to provide a voltage gain across a load. The waveform generator has a primary side circuit comprising a first inductor. The waveform generator has a secondary side circuit comprising a second inductor, a first output region conductively coupled to the load, and a second output region conductively coupled to the load. The second inductor is inductively coupled to the first inductor. The first inductor is conductively coupled to the first output region so as to supply a first of the two waveforms to the load. The second inductor is conductively coupled to the second output region so as to supply a second of the two waveforms to the load. A system incorporating the waveform generator and a method of driving the waveform generator are also provided.

Abstract: An ion filter for filtering ions in a gas sample. The ion filter has a first ion channel for filtering ions from a target chemical in the gas sample. The ion filter has a second ion channel for filtering ions from the target chemical in the gas sample. The second ion channel is separated from the first ion channel. A temperature control region is in thermal contact with the first and second ion channels for controlling a difference in temperature between the first and second ion channels. A method of filtering ions from a target chemical in a gas sample is also provided.

Abstract: The waveform generator (10) comprises a switch (13). The waveform generator (10) comprises a transformer (15) having a primary side circuit and a secondary side circuit. The primary side circuit has a first terminal arranged to be conductively coupled to a DC voltage source, and a second terminal conductively coupled to the switch (13). The waveform generator (10) further comprises a controller (11) arranged to supply a drive signal to the switch for switching the switch between on and off states. The controller (11) is arranged to adjust the frequency of the drive signal so as to control at least one of the peak voltage and the duty cycle of a waveform generated by the waveform generator (10). The frequency of the drive signal may be adjusted as the voltage level of the DC voltage source remains constant. The frequency of the drive signal may be adjusted in response to a change in the voltage level of the DC voltage source.

Abstract: A method of manufacture for a ion mobility filter is disclosed. The method of manufacturing an ion filter for a spectrometry system includes providing a sheet of conductive material and defining a plurality of ion filters on the sheet. The definition of the plurality of ion filters is achieved by forming an electrode layer for each ion filter on the sheet, where each electrode layer comprises at least one ion channel and an isolation channel surrounding the at least one ion channel. A support layer on each electrode layer is also formed. Each support layer comprises an aperture at least partially aligned with the at least one ion channel. The ion filter is then separated. The risk of contaminants entering the at least one ion channel when separating the ion filters is reduced by surrounding the at least one ion channel with the isolation channel.

Abstract: A sensor system comprising a housing having an inlet aperture through which fluid enters the housing and a conditioning material in the housing, the conditioning material being adapted to control levels of a substance within the housing. The sensor system comprises a sensor for analysing the fluid in the housing. The sensor system comprises circulation means which is configured to alternate circulation of fluid within the housing between a sensing fluid path in which the fluid is analysed by the sensor and a second fluid path in which the fluid flow is conditioned. A method for analysing fluid in a housing using a sensor is also provided.

Abstract: We describe a method and apparatus for detecting humidity using a Field Asymmetric Ion Mobility Spectrometry (FAIMS) system. The system may comprise an ionizer for generating ions within a gas sample, wherein each ion has an associated ion mobility; an ion filter for separating the ions by applying a compensation field and a dispersion field to the generated ions; a detector for detecting an output from the ion filter; and a processor.

Abstract: Mobile device (110) is disclosed. The present techniques relate to a mobile device or portable electronic device, particularly a device including a breath sampling device. The mobile electronic device (110) comprises a collection device (112) for collecting and storing a gas sample. The collection device (112) is accessible to enable analysis of the gas stored in the collection device (112). The collection device (112) comprises a mouthpiece (118) into which a user exhales. The collection device (112) further comprises a plurality of sorbent tubes (114) to collect and store the breath sample(s). Each tube (114) has a one-way valve (116) to prevent captured breath escaping.

Abstract: A method of manufacture for a ion mobility filter is disclosed. The method of manufacturing an ion filter for a spectrometry system includes providing a sheet of conductive material and defining a plurality of ion filters on the sheet. The definition of the plurality of ion filters is achieved by forming an electrode layer for each ion filter on the sheet, where each electrode layer comprises at least one ion channel and an isolation channel surrounding the at least one ion channel. A support layer on each electrode layer is also formed. Each support layer comprises an aperture at least partially aligned with the at least one ion channel. The ion filter is then separated. The risk of contaminants entering the at least one ion channel when separating the ion filters is reduced by surrounding the at least one ion channel with the isolation channel.

Abstract: An ion filter for filtering ions in a gas sample. The ion filter has a first ion channel for filtering ions from a target chemical in the gas sample. The ion filter has a second ion channel for filtering ions from the target chemical in the gas sample. The second ion channel is separated from the first ion channel. A temperature control region is in thermal contact with the first and second ion channels for controlling a difference in temperature between the first and second ion channels. A method of filtering ions from a target chemical in a gas sample is also provided.

Abstract: An ion mobility filter is disclosed. The present invention relates to but not exclusively a field asymmetric ion spectrometry filter. For example, we describe an ion filter for filtering ions in a gas sample. The ion filter is comprised of a plurality of electrodes, a first ion channel, and a second ion channel. The first ion channel filters ions from a target chemical in the gas sample, defines a gap between a first pair of electrodes in the plurality of electrodes, and has a first ion channel gap width. The second ion channel filters ions from the target chemical in the gas sample, defines a gap between a second pair of electrodes in the plurality of electrodes, and has a second ion channel gap width. The first ion channel gap width is greater than the second ion channel gap width.

Abstract: A waveform generator configured to generate two waveforms of opposite polarity so as to provide a voltage gain across a load. The waveform generator has a primary side circuit comprising a first inductor. The waveform generator has a secondary side circuit comprising a second inductor, a first output region conductively coupled to the load, and a second output region conductively coupled to the load. The second inductor is inductively coupled to the first inductor. The first inductor is conductively coupled to the first output region so as to supply a first of the two waveforms to the load. The second inductor is conductively coupled to the second output region so as to supply a second of the two waveforms to the load. A system incorporating the waveform generator and a method of driving the waveform generator are also provided.

Abstract: A method and sensor for monitoring chemical species in a gas flow are described. An ionized sample of gas is passed through a flow channel, with a DC electric field applied transverse to the longitudinal axis of the channel. Any electric current produced by the ion flow is measured, with variations in the current being indicative of a change in composition of the gas flow. In certain embodiments, the DC field may be varied over time, to sweep the field voltage. The detected current against field voltage graph may be taken as a profile of a particular gas composition. Variations in the profile again are indicative of a change in gas composition.