Abstract: According to an aspect of the present inventive concept there is provided a probe for analysis of a liquid in a mixture of the liquid and solid substance. The probe comprises: a tube comprising a sample end configured to be inserted into the mixture; a cap configured to come into contact with the mixture at the sample end, the cap comprising one or more openings configured for allowing passage of the liquid therethrough, and for preventing passage of the solid substance therethrough; and an optical measurement head arranged in the tube and configured to come into contact with the liquid having passed the one or more openings, wherein the optical measurement head is configured to collect measurement information for analysis of the liquid.

Abstract: A device for dielectric material characterization of a test sample is provided. The device comprises a resonator block comprising a groove at at least one side of the resonator block, wherein the groove comprises at least a first inclined surface and a second inclined surface and is configured to contact the test sample via the first inclined surface and/or the second inclined surface. In this regard, the resonator block is configured to generate a rotational electric field coupled between the first inclined surface and the second inclined surface of the groove and further to propagate the rotational electric field partially or fully through the test sample in order to perform dielectric material characterization of the test sample.

Abstract: A circuit for optoelectronic down-conversion of a terahertz, THz, signal comprises a first photodiode and a second photodiode configured to be excited by an optical beat signal. The photodiodes are coupled in series through a common antenna. The terminals of the antenna are coupled to form an output terminal and the antenna is configured to receive the terahertz, THz, signal. The photodiodes thereby, via the optical beat signal, respectively, down-convert the THz signal and generate a current comprising an intermediate frequency, IF, component and a direct current, DC, component. The respective generated currents are summed at the output terminal, thereby obtaining the IF components and cancelling the DC components.

Abstract: A circuit for optoelectronic down-conversion of a terahertz, THz, signal comprises a first photodiode and a second photodiode configured to be excited by an optical beat signal. The photodiodes are coupled in series through a common antenna. The terminals of the antenna are coupled to form an output terminal and the antenna is configured to receive the terahertz, THz, signal. The photodiodes thereby, via the optical beat signal, respectively, down-convert the THz signal and generate a current comprising an intermediate frequency, IF, component and a direct current, DC, component. The respective generated currents are summed at the output terminal, thereby obtaining the IF components and cancelling the DC components.

Abstract: A solid-state device for photo detection, in general, of terahertz radiation is disclosed. One aspect is a detector device comprising a body having a photoconductive material, a first antenna element connected to a first portion of the body, and a second antenna element connected to a second portion of the body. The first antenna element and the second antenna element are arranged to induce an electric field in the body in response to an incident signal. Further, the device has a waveguide arranged to couple light into the photoconductive material via a coupling interface between the waveguide and the body, where the coupling interface faces away from the first portion and the second portion of the body and is closer to the first portion than to the second portion.

Abstract: A solid-state device for photo detection, in general, of terahertz radiation is disclosed. One aspect is a detector device comprising a body having a photoconductive material, a first antenna element connected to a first portion of the body, and a second antenna element connected to a second portion of the body. The first antenna element and the second antenna element are arranged to induce an electric field in the body in response to an incident signal. Further, the device has a waveguide arranged to couple light into the photoconductive material via a coupling interface between the waveguide and the body, where the coupling interface faces away from the first portion and the second portion of the body and is closer to the first portion than to the second portion.

Abstract: The disclosed technology generally relates to sensors comprising a two-dimensional electron gas (2DEG), and more particularly to an AlGaN/GaN 2DEG-based sensor for sensing signals associated with electrocardiograms, and methods of using the same. In one aspect, a sensor comprises a substrate and a GaN/AlGaN hetero-junction structure formed on the substrate and configured to form a two-dimensional electron gas (2DEG) channel within the GaN/AlGaN hetero-junction structure. The sensor additionally comprises Ohmic contacts connected to electrical metallizations and to the 2DEG channel, wherein the GaN/AlGaN hetero-junction structure has a recess formed between the Ohmic contacts. The sensor further comprises a dielectric layer formed on a top surface of the sensor.

Abstract: The disclosed technology generally relates to a sensor and methods for making and using the same, and more particularly relates to a sensor configured to sense the presence of at least one fluidum. In one aspect, a sensor for sensing a fluidum in a space adjoining the sensor comprises a two-dimensional electron gas (2DEG) layer stack. The sensor additionally comprises a gate lying adjacent to at least part of the 2DEG layer stack and configured to electrostatically control the electron density of a two-dimensional electron gas (2DEG) in the 2DEG layer stack. The sensor further comprises a source electrode contacting the 2DEG layer stack for electrically contacting the 2DEG.

Abstract: The application describes methods and apparatus for chemical sensing, e.g. gas sensing, which have high sensitivity but low power operation. A sensor is described having a flexible membrane comprising a III/N heterojunction structure configured so as to form a two dimensional electron gas within said structure. A sensing material is disposed on at least part of the flexible membrane, the sensing material being sensitive to one or more target chemicals so as to undergo a change in physical properties in the presence of said one or more target chemicals. The sensing material is coupled to said heterojunction structure such that said change in physical properties of the sensing material imparts a change in stress within the heterojunction structure which modulates the resistivity of the two dimensional electron gas.

Abstract: A Sensor for sensing the presence of at least one fluidum in a space adjoining the sensor is disclosed. In one aspect, the sensor has a two-dimensional electron gas (2DEG) layer stack, a gate electrode overlaying at least part of the 2DEG layer stack for electrostatically controlling electron density of a 2DEG in the 2DEG layer stack and a source and a drain electrode contacting the 2DEG layer stack for electrically contacting the 2DEG, wherein a detection opening is provided in between the gate electrode and the 2DEG layer stack and wherein the detection opening communicates with the space through a detection opening inlet such that molecules of the fluidum can move from the adjoining space through the detection opening inlet into the detection opening where they can measurably alter a electric characteristic of the 2DEG.

Abstract: The disclosed technology generally relates to sensors comprising a two-dimensional electron gas (2DEG), and more particularly to an AlGaN/GaN 2DEG-based sensor for sensing signals associated with electrocardiograms, and methods of using the same. In one aspect, a sensor comprises a substrate and a GaN/AlGaN hetero-junction structure formed on the substrate and configured to form a two-dimensional electron gas (2DEG) channel within the GaN/AlGaN hetero-junction structure. The sensor additionally comprises Ohmic contacts connected to electrical metallizations and to the 2DEG channel, wherein the GaN/AlGaN hetero-junction structure has a recess formed between the Ohmic contacts. The sensor further comprises a dielectric layer formed on a top surface of the sensor.

Abstract: The disclosed technology generally relates to a sensor and methods for making and using the same, and more particularly relates to a sensor configured to sense the presence of at least one fluidum. In one aspect, a sensor for sensing a fluidum in a space adjoining the sensor comprises a two-dimensional electron gas (2DEG) layer stack. The sensor additionally comprises a gate lying adjacent to at least part of the 2DEG layer stack and configured to electrostatically control the electron density of a two-dimensional electron gas (2DEG) in the 2DEG layer stack. The sensor further comprises a source electrode contacting the 2DEG layer stack for electrically contacting the 2DEG.

Abstract: The present disclosure relates to a gas sensor including a first layer and a second layer superimposed on each other along an interface between the two layers. The first layer includes an array of nanoparticles along the interface, the nanoparticles provided so as to allow, upon illumination with electromagnetic radiation, long range diffractive coupling of surface plasmon resonances resulting in a surface lattice resonance condition. The second layer includes a material that, when exposed to at least one predetermined gas, detectably affects the surface lattice resonance condition. The material of the second layer preferably has a porosity of at least 10%.

Abstract: Methods and sensors for detecting the presence and/or concentration of an analyte are disclosed. In one aspect, a sensing element for use in a sensor is disclosed. The sensing element comprises a resonant cavity device configured to emit optical radiation at an initial power level, a sensing layer exhibiting an initial refractive index, and a detector. The sensing layer is configured to absorb or adsorb an analyte and, in response to absorbing or adsorbing the analyte, exhibit a modified refractive index that differs from the initial refractive index. The resonant cavity device is further configured to, in response to the sensing layer absorbing or adsorbing the analyte, emit optical radiation at a modified power level based on the modified refractive index. The detector is configured to detect the modified power level.

Abstract: A Sensor for sensing the presence of at least one fluidum in a space adjoining the sensor is disclosed. In one aspect, the sensor has a two-dimensional electron gas (2DEG) layer stack, a gate electrode overlaying at least part of the 2DEG layer stack for electrostatically controlling electron density of a 2DEG in the 2DEG layer stack and a source and a drain electrode contacting the 2DEG layer stack for electrically contacting the 2DEG, wherein a detection opening is provided in between the gate electrode and the 2DEG layer stack and wherein the detection opening communicates with the space through a detection opening inlet such that molecules of the fluidum can move from the adjoining space through the detection opening inlet into the detection opening where they can measurably alter a electric characteristic of the 2DEG.

Abstract: The present invention relates to a gas sensing device comprising a nanoparticle layer (1) and a quantum dot layer (3) separated from each other by a gas absorption layer (2) which has a thickness which changes upon absorption of a gas. The nanoparticle layer (1) is provided for generating a surface plasmon resonance within a plasmon resonance frequency range upon illumination with light within a light frequency range; the quantum dot layer (3) has an absorption spectrum overlapping with said plasmon resonance frequency range of said nanoparticle layer (1) and shows photoluminescence in a photoluminescence emission frequency range upon absorption of energy within its absorption spectrum. The present invention further relates to a method for fabricating such a gas sensing device and to a method of using such a gas sensing device.

Abstract: A device including a gas sensor sensitive to the presence of a specific gas is disclosed. In one aspect, the gas sensor includes a first segment made of a dielectric material and a second segment made of a semiconducting material. The first segment has a first surface exposed to an environment of the gas sensor and is located between the environment and the second segment. The first segment has a first thickness and the second segment has a second thickness. The first thickness is selected such that upon diffusion of a gas molecule of the specific gas into the first segment, a dipole of the molecule of the specific gas detectably influences a bending of an energy-band structure of the semiconducting material of the second segment. The second thickness is in the order of, or smaller than, the Debye length of the semiconducting material.

Abstract: Methods and sensors for detecting the presence and/or concentration of an analyte are disclosed. In one aspect, a sensing element for use in a sensor is disclosed. The sensing element comprises a resonant cavity device configured to emit optical radiation at an initial power level, a sensing layer exhibiting an initial refractive index, and a detector. The sensing layer is configured to absorb or adsorb an analyte and, in response to absorbing or adsorbing the analyte, exhibit a modified refractive index that differs from the initial refractive index. The resonant cavity device is further configured to, in response to the sensing layer absorbing or adsorbing the analyte, emit optical radiation at a modified power level based on the modified refractive index. The detector is configured to detect the modified power level.

Abstract: A gas ionization sensor is disclosed. In one aspect, the sensor includes at least one sensing element on a substrate. The sensing element includes: at least one nanowire and a counter electrode which surrounds the nanowire, the surrounding electrode being electrically isolated from the nanowire and being at a predetermined gap from the nanowire, the gap allowing penetration of a gas or a gas mixture between the nanowire and the surrounding electrode. The sensing element also includes a voltage source electrically connected between the nanowire and the surrounding electrode for providing a voltage difference between the nanowire and the surrounding electrode, and measurement circuitry for measuring a breakdown voltage and/or an electrical discharge current and/or a prebreakdown current through the gap.

Abstract: The present disclosure relates to a gas sensor including a first layer and a second layer superimposed on each other along an interface between the two layers. The first layer includes an array of nanoparticles along the interface, the nanoparticles provided so as to allow, upon illumination with electromagnetic radiation, long range diffractive coupling of surface plasmon resonances resulting in a surface lattice resonance condition. The second layer includes a material that, when exposed to at least one predetermined gas, detectably affects the surface lattice resonance condition. The material of the second layer preferably has a porosity of at least 10%.