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The purpose of this paper is a new thin-film based sensor proposed for sensitive and selective detection of mercury (Hg²⁺) ions in water. The thin-film platform is easy to use and quick for heavy metal ions (HMIs) detection in the picomolar range. Ion-selective self-assembled monolayer's (SAM) of thiol used for the detection of HMIs above the Au/Ti top surface.

A thin-film based platform is suitable for the on-field experiments and testing of water samples. HMIs (antigen) and thiol-based SAM (antibody) interaction results change in surface morphology and topography. In this study, the authors have used different characterization techniques to check the selectivity of the proposed method. This change in the morphology and topography of thin-film sensor checked with Fourier-transform infrared spectroscopy, surface-enhanced Raman scattering spectroscopy, atomic force microscopy and scanning electron microscopy with energy dispersive x-ray analysis used for high-resolution images.

This thin-film based platform is straightforward to use and suitable for real-time detection of HMIs at the picomolar range. This thin-film based sensor platform capable of achieving a lower limit of detection (LOD) 27.42 ng/mL (136.56 pM) using SAM of Homocysteine-Pyridinedicarboxylic acid to detect Hg²⁺ ions.

A thin-film based technology is perfect for real-time testing and removal of HMIs, but the LOD is higher as compared to microcantilever-based devices.

The excessive use and commercialization of nanoparticle (NPs) are quickly expanding their toxic impact on health and the environment. The proposed method used the combination of thin-film and NPs, to overcome the limitation of NPs-based technique and have picomolar (136.56 pM) range of HMIs detection. The proposed thin-film-based sensor shows excellent repeatability and the method is highly reliable for toxic Hg²⁺ ions detection. The main advantage of the proposed thin-film sensor is its ability to selectively remove the Hg²⁺ ions from water samples just like a filter and a sensor for detection at picomolar range makes this method best among the other current-state of the art techniques.

Development of thin film sensors with pH function for noninvasive real-time monitoring of spoilage of packed seafood such as fish, crab and shrimp are described in this study. It is also the purpose of this study to enhance the leaching resistance of the sensors by using a suitable strategy and to quantitatively correlate the sensor’s halochromism with the total volatile amine.

To prepare halochromic sensors with better leaching resistance, biocompatible materials such as starch, agar, polyvinyl alcohol and cellulose acetate along with a halochromic dye were used to prepare the thin film sensors. These thin films were evaluated for monitoring the spoilage of packed seafood at room temperature, 4°C and −2°C up to 30 days. The halochromic sensors were characterized using UV-visible and FT-IR spectroscopy.

CIELab analyses of the halochromism of the thin film sensors revealed that the color changes exhibited by the sensors in response to the spoilage of seafood are visually distinguishable. Further, the halochromic response of the thin films was directly proportional to the amount of total volatile base nitrogen that evolved from the packed seafood. Excellent leaching resistance was observed for the developed thin film sensors. The halochromic property of the sensors is reversible and thus the sensors are recyclable. Besides, the thin film sensors exhibited significant biodegradability.

This study provides insights for use of different biocompatible polymers for obtaining enhanced leaching resistance in halochromic sensors. Further, the color changes exhibited by the sensors are in line with the total volatile amines evolved from the packed seafood. These results highlight the importance of the developed halochromic thin film sensors for real-time monitoring of the spoilage of packed seafood.

The measurement of heat flux is of importance to the development of aerospace engine as basic physical quantities in extreme environment. Heat radiation is one of the basic forms of heat transfer phenomenon. The structure optimizing can improve the performance and infrared absorptivity of the thin film sensor.

This paper designed one kind of thin film heat flux sensor (HFS) with antireflective coating based on transparent conductive oxide thermopile. The introduced membrane structure is so thin that it has little impact on sensor performance. Fabrication of thin film sensors were fabricated by physical vapor deposition (PVD) process.

The steady-state and dynamic response characteristics of the HFS were investigated by calibration platform. The experimental results shown that the absorptivity of the membrane structure (for1070nm) improved compared with that before optimization. The sensitivity of heat flux gauge was 48.56 µV/ (kW/m2) and its frequency response was determined to be about 1980 Hz.

The thin film HFS uses thermopile based on Indium Tin Oxid and In2O3. The antireflective coating is introduced to hot endpoint of HFS to improve sensitivity on laser thermal source. The infrared optical properties of membrane layer structure were investigated. The steady-state and the transient response characteristics of the heat flux sensor were also investigated.

The purpose of this paper is to report on metal‐oxide‐semiconductor (MOS) capacitor‐based O₂ sensors with different catalytic metal electrode (Al or Pd), deposited on both smooth and porous surface (pore diameter ranging from 2.76 to 71.6 μm) of ZrO₂ thin film.

The ZrO₂ thin film has been prepared by RF sputtering and DC magnetron sputtering process followed by thermal oxidation process, whereas the electrodes were deposited on thin film by thermal evaporation. The sensors are exposed to O₂ gas ambient at room temperature and the O₂ sensing performance has been examined by surface characterizations and on‐line sensing electrical characterizations.

MOS capacitor O₂ sensor with Pd electrode on porous ZrO₂ thin film has the best sensitivity in term of both adsorption and desorption of gas. This sensor is proved to be operated in both capacitor and diode modes.

The paper demonstrates that room temperature MOS‐based O₂ sensor operates in capacitor and diode mode conditions with focus on the effect of ZrO₂ surface morphology on the sensing properties.

Regular monitoring of bacteria, especially Escherichia coli, in wastewater is crucial to ensure the maintenance of public health. Amperometric detection proves to be a fast, sensitive and economically viable solution for E. coli enumeration. This paper reported a prototype amperometric sensor based on PANI-ZnO-NiO nanocomposite thin films prepared by sol–gel method and irradiated with gamma ray. The purpose of this study is to investigate the sensor performance of PANI-ZnO-NiO nanocomposite thin films to detect E. coli in water.

The films were varied with different compositions of ZnO and NiO by using the formula PANI-(ZnO)_1-x-(NiO)_x, with x = 0.2, 0.4, 0.6 and 0.8. PANI-ZnO-NiO nanocomposite thin films were characterized by using X-ray diffraction (XRD) and atomic force microscopy (AFM) to study the crystallinity and surface morphology of the films. The sensor performance was conducted using the current–voltage (I-V) measurement by testing the films in clean water and E. coli solution.

XRD diffractograms show the peaks of ZnO (1 0 0) and NiO (1 0 2). AFM analysis shows the surface roughness, and the grain size of PANI-ZnO-NiO thin films decreases when the concentration ratios of NiO increased. I-V curves show the difference in current flow, where the current in E. coli solution is higher than the clean water.

PANI-(ZnO)_1-x-(NiO)_x nanocomposite thin film with the highest concentration of ZnO performed the highest sensitivity among the other concentrations, which can be used to indicate the presence of E. coli bacteria in water.

It is often important to acquire information such as temperature and strain values from metallic tools and structures in situ. With embedded sensors, structures are capable of monitoring parameters at critical locations not accessible to ordinary sensors. To embed sensors in the functional structures, especially metallic structures, layered manufacturing is a methodology capable of rapidly and economically integrating sensors during the production of tooling or structural components. Embedding techniques for both fiber‐optic sensors and thin‐film sensors have been developed.

The present study aims to describe the development of halochromic thin film sensors using mixed indicator dyes for monitoring the spoilage of packed seer fish.

Thin film was prepared using renewable polysaccharide incorporated with mixed indicator dyes. The thin film was characterized using ultraviolet visible and Fourier transform-infrared spectroscopy. The characteristics of the thin film were studied by analyzing the CIELAB and Red Green Blue values and biodegradability. The thin films were evaluated for real-time monitoring of the spoilage of packed seer fish.

The thin film sensors were found to exhibit excellent halochromism. The color changes were visible and distinguishable. The sensors responded efficiently for real-time monitoring of spoilage of fish by showing unique color changes.

This study provides promising mixed indicator that exhibits different colors in the alkaline pH. Also the present study reveals a potential combination of materials for preparation of halochromic sensors that can be used for monitoring the spoilage of packed seer fish in real time.

The flexibly thin film grid pressure sensor is mainly used to detect the interface pressure distribution between touching objects. Aim at larger measurement error, the strip double sensing layer pressure sensor are designed and fabricated and tested.

Defects and characteristic of the flexibly thin film grid pressure sensor based on piezoresistive effect are analyzed and pointed out in this paper. After comparison of four sensors, the strip double sensing layer pressure sensor was thought to be best.

Experiment shows that the strip double sensing layer pressure sensor could eliminate the measurement error basically and illustrates the validity of measuring the interface pressure distribution between area touching objects.

In this paper, only the strip double sensing layer pressure sensor was used to verify the validity of measuring the static interface pressure distribution between peach and platform. But there also exists some problems such as the adhering reliability of electrode and the unevenness of sensing layer. These problems could be overcome in the future research if the fabricating procedure and ingredient of material could be adjusted correctly.

The strip double sensing layer pressure sensor could be applied to detect the static interface pressure distribution such as peach pressure distribution. For dynamic measurement, this research needs to be done further.

Strip double sensing layer pressure sensor with simple “interlayer” structure and with low manufacture cost is presented to basically eliminate the measurement error of interface pressure distribution of original sensor.

Detecting O₂ gas in a confined space at room temperature is particularly important to monitor the work process of precision equipment. This study aims to propose a miniaturized, low-cost, mass-scale produced O₂ sensor operating around 30°C.

The O₂ sensor based on lanthanum fluoride (LaF₃) solid electrolyte thin film was developed using MEMS technology. The principle of the sensor was a galvanic cell H₂O, O₂, Pt | LaF₃ | Sn, SnF₂ |, in which the Sn film was prepared by magnetron sputtering, and the LaF₃ film was prepared by thermal resistance evaporation.

Through pretreatments, the sensor’s response signal to 40% oxygen concentration was enhanced from 1.9 mV to 46.0 mV at 30°C and 97.0% RH. Tests at temperatures from 30°C to 50°C and humidity from 32.4% RH to 97.0% RH indicated that the output electromotive force (EMF) has a linear relationship with the logarithm of the oxygen concentration. The sensitivity of the sensor increases with an increase in both humidity and temperature in the couple mode, and the EMF of the sensor follows well with the Nernst equation at different temperatures and humidity.

This research could be applied to monitor the oxygen concentration below 25% in confined spaces at room temperature safely without a power supply.

The relationship between temperature and humidity coupling and the response of the sensor was obtained. The nano-film material was integrated with the MEMS process. It is expected to be practically applied in the future.

Atmospheric dependent, gas sensitive resistors seem to be good candidates for detecting critical air pollution levels. Recently, great progress has been made in the development of various sensor types, but less attention seems to be paid to the integration of sensor elements with different characteristics. The aim of this international project is to develop a smart hybrid gas multi‐sensor module for environmental applications, i.e. by combining classical thick‐ and thin‐film elements with polymer‐film based sensors and also a signal processing ASIC within a single package, which should be useful for all sensor types. The module should enable multi‐sensor operation as well, when connected to an intelligent signal‐processing unit.