Abstract: A gas sensor configured to detect a target gas in a gaseous atmosphere, for example NO2 or O3 in air, comprises: a transparent substrate; a gas sensitive detection layer supported by the transparent substrate, the gas sensitive detection layer comprising i) a gas sensitive detection material having an electrical impedance which is sensitive to the target gas and ii) connections configured to allow for detection of electrical impedance of the gas sensitive detection material; and a light source, for example a LED, configured to provide light to the gas sensitive detection layer through the transparent substrate. The gas sensor may operate at room temperature whilst requiring little power.

Abstract: A sensing apparatus for detecting at least one target molecule in a gaseous medium is provided, comprising an optical fiber having a core with a tilted grating, and a coating assembly. The coating assembly has a composite film layer having an outer surface in direct contact with the gaseous medium, and contains at least two compositions mixed with one another therein, which include one or more surface plasmon resonance (SPR)-active compositions and one or more reacting compositions that are reversibly reactive to the at least one target molecule. Depending on different reacting compositions, the sensing apparatus can detect various target gas molecules such as hydrogen, ammonia, methane, and formaldehyde, etc. The sensing apparatus has relatively fast response time and high resistance to deactivation. A sensing system based on the sensing apparatus, a manufacturing method of the sensing apparatus, and a detection method using the sensing system, are further provided.

Abstract: A sensing apparatus for detecting at least one target molecule in a gaseous medium is provided, comprising an optical fiber having a core with a tilted grating, and a coating assembly. The coating assembly has a composite film layer having an outer surface in direct contact with the gaseous medium, and contains at least two compositions mixed with one another therein, which include one or more surface plasmon resonance (SPR)-active compositions and one or more reacting compositions that are reversibly reactive to the at least one target molecule. Depending on different reacting compositions, the sensing apparatus can detect various target gas molecules such as hydrogen, ammonia, methane, and formaldehyde, etc. The sensing apparatus has relatively fast response time and high resistance to deactivation. A sensing system based on the sensing apparatus, a manufacturing method of the sensing apparatus, and a detection method using the sensing system, are further provided.

Abstract: A sensing apparatus, system, and use method for selective detection of a target molecule in a gaseous medium with a limit of detection of less than 50 ppm are provided. The sensing apparatus comprises an optical fiber having a core with a tilted grating, and a coating assembly that is both active to surface plasmon resonance (SPR) and reversibly reactive to the target molecule to allow for repeated detection. Upon a compatible light propagating in the optical fiber, surface plasmon waves at an interface between the coating assembly and the medium can be generated to thereby derive information of the target molecule. Signals from core mode optical waves can additionally be used as inherent reference to remove influences of fluctuations from environmental factors and input power level. There is at least one range of concentrations for the target molecule allowing for linear measurement. Multiplexing of a plurality of sensing apparatuses is also disclosed.

Abstract: Force transducer (10) include two structural members (11, 12) spaced apart to define a gap (101) and being linked to each other. Optical fibers (13) are to the members and are freely suspended in the gap. The optical fibers are configured to provide a change in a detectable optical property responsive to a change in relative position between the two members in one or more predetermined degrees of freedom. Each of the optical fibers (13) is fixed to both structural members and continuous between the members to link the two structural members to each other. The optical fibers are substantially the only structure forming a link between the two structural members (11, 12), such that the arrangement of the optical fibers defines substantially the stiffness of the link between the two structural members in the one or more predetermined degrees of freedom, which stiffness is mainly, such as for at least 95%, determined by the optical fibers.

Abstract: The present invention relates to gas sensors, in particular, to an optical fibre sensor for measuring the presence and/or quantity of one of more gasses, the gas sensor comprising an optical fibre, and a gas sensitive detection material at a portion of the surface of the optical fibre, said gas sensitive detection material comprising a gas sensitive reactant and a porous matrix, wherein the gas sensitive detection material undergoes a reversible change of reflectance and/or absorbance at a detection wavelength when subjected to a gas to be detected.

Abstract: Force transducer (10) include two structural members (11, 12) spaced apart to define a gap (101) and being linked to each other. Optical fibres (13) are to the members and are freely suspended in the gap. The optical fibres are configured to provide a change in a detectable optical property responsive to a change in relative position between the two members in one or more predetermined degrees of freedom. Each of the optical fibres (13) is fixed to both structural members and continuous between the members to link the two structural members to each other. The optical fibres are substantially the only structure forming a link between the two structural members (11, 12), such that the arrangement of the optical fibres defines substantially the stiffness of the link between the two structural members in the one or more predetermined degrees of freedom, which stiffness is mainly, such as for at least 95%, determined by the optical fibres.