An apparatus and method comprising: a plurality of sensor elements wherein the sensor elements are configured to be actuated in response to exposure to a parameter and the apparatus is configured to record when each of the sensor elements are actuated wherein: the plurality of sensor elements comprises at least a first subset of sensor elements and at least a second subset of sensor elements where the first subset of sensor elements are actuated in response to a first level of exposure to a parameter and the second subset of sensor elements are actuated in response to a second level of exposure to a parameter.

The invention discloses a humidity sensor based on squaraine polymer and the preparation method and use thereof. Specifically, the humidity sensor disclosed by the invention comprises a coating material and an interdigital electrode, wherein the coating material is a squaraine polymer as shown in formula I, n is an integer of 40-50, the coating material is brushed on the interdigital electrode, and the thickness is 100-400 microns. The humidity sensor disclosed by the invention has the advantages that the preparation is convenient, and the operation is simple; the response time is short, and the response for humidity change is higher than that of common metallic oxides; the recovery time is short, and the device performance is stable; the humidity hysteresis of the device is high under high humidity environment.

The present invention relates to a method for measuring metal ion permeability of a polymer film, comprising the steps of: applying a voltage to the polymer film at a temperature of 5° C. to 250° C., while one side of the polymer film is brought into contact with an electrolyte comprising metal ions, an organic solvent and an aqueous solvent; and measuring the change rate of resistance or change rate of current of the polymer film according to time, after the voltage is applied, and a device for measuring metal ion permeability of a polymer film used therefor.

Miniature resistive gas detectors incorporate thin films that can selectively identify specific gases when heated to certain characteristic temperatures. A solid state gas sensor module is disclosed that includes a gas sensor, a heater, and a temperature sensor, stacked over an insulating recess. The insulating recess is partially filled with a support material that provides structural integrity. The solid state gas sensor module can be integrated on top of an ASIC on a common substrate. With sufficient thermal insulation, such a gas detector can be provided as a low-power component of mobile electronic devices such as smart phones. A method of operating a multi-sensor array allows detection of relative concentrations of different gas species by either using dedicated sensors, or by thermally tuning the sensors to monitor different gas species.

The sensitivity of a graphene gas sensor to a gas analyte molecule may be significantly enhanced using molecular doping, which may be as effective as substitutional doping and more effective than electric-field doping. In particular, the room temperature sensitivity of NO.sub.2-doped graphene to NH.sub.3 was measured to be comparable to the sensitivity of graphene doped with substitutional boron atoms and superior to that of undoped graphene by an order of magnitude. The detection limit for NO.sub.2-doped graphene gas sensors was estimated to be about 200 ppb, which may be improved with extended exposure to NO.sub.2, compared to a detection limit of about 1.4 ppm for undoped graphene. While the stability analysis of NO.sub.2-doped graphene sensors indicates that the doping method may not be completely stable, molecular doping is nevertheless a candidate technique for sensitivity improvement by enhancing the initial carrier concentration.

Systems and methods for monitoring a filter in, for example, an immersion cooled system are described. In one embodiment the application pertains to a process comprising employing a filter media to filter fluid wherein one or more electrical properties change depending upon pH of the filter fluid. The one or more electrical properties may be measured to monitor the filter. If desired, the filter media's electrical properties may be modified based on the configuration of the filter to facilitate the measurements.

A gas-detecting apparatus includes a measurement circuit including a gas sensor and a measurement instrument and a decision circuit. Detection cells, included in the gas sensor, each include a first electrode, a second electrode having a surface exposed from an insulation layer, and a metal oxide layer disposed between the first electrode and the second electrode. The resistance values of the detection cells are each allowed to decrease by a contact of gas containing hydrogen atoms with the second electrode. The measurement instrument monitors the resistance values of the detection cells. The decision circuit decides whether the gas is detected or not based on at least one change of the resistance values.

A gas-detecting apparatus includes a gas sensor and a power supply circuit. The gas sensor includes: a first electrode; a second electrode; a metal oxide layer disposed between the first electrode and the second electrode; and an insulation film covering the first electrode, the second electrode, and the metal oxide layer. The insulation file having an opening from which a surface of the second electrode is exposed. The resistance value of the metal oxide layer decreases when gas containing hydrogen atoms comes into contact with the second electrode. The power supply circuit applies a predetermined voltage between the first electrode and the second electrode to increase the resistance value of the metal oxide layer before and/or after the decrease in the resistance value of the metal oxide layer.

A gas sensor includes a first electrode disposed on a substrate, a second electrode disposed on the substrate and spaced apart from the first electrode, and a sensitive member disposed on the substrate. The sensitive member contacts first and second electrodes and has a porous structure from a three-dimensional (3D) arrangement of shells including a gas-sensitive material. A thickness of the sensitive member is 5 μm to 10 μm, and a thickness of the shells is 10 nm to 40 nm.

The present invention relates to sensor arrays that are more accurate, more sensitive, and more specific with respect to the material that is detected and capable of detecting one or more materials over a wide range. Such sensor arrays can comprises sensors comprising pattern illumination-based annealed coated substrate and one or more functional molecules and process of using same. The method of designing and process of making the sensors for such sensor array yields components that can have one or more electronic and/or optical functionalities that are integrated on the same substrate or film and to which one or more functional molecules can be attached to yield a sensor. Such processes when coupled with the design methods provided herein, allow for the rapid, efficient device prototyping, design change and evolution in the lab and on the production side.