Detection of LPG Gas by Using Multi Sensors Array and Fabricated ZnO Gas Sensor

The demand for LPG (Liquefied Petroleum Gas) detection constitutes a major and critical problem in the field of gas detection. LPG is used for domestic appliances used in the heating of buildings, producing petrochemicals and as a motor fuel. The current paper used the fabricated ZnO, in addition to TGS 813, TGS 2600, TGS 4160, TGS 3870, TGS 822 as semiconductor gas sensors, in varying temperature and load resistance in a prototype setup so as to explore each model’s accuracy for performance prediction for gas detection. The fabricated ZnO gas sensor is used also to detect the LPG. The comparison is done between gas sensors array and the fabricated one from ZnO. The actual results are put in comparison with the empirical algorithms’ predictions. The optimal model is found to be the full quadratic empirical model based on the lowest error with different sensors.

Combination of Ceramic Laser Micromachining and Printed Technology as a Way for Rapid Prototyping Semiconductor Gas Sensors

The work describes a fast and flexible micro/nano fabrication and manufacturing method for ceramic Micro-electromechanical systems (MEMS)sensors. Rapid prototyping techniques are demonstrated for metal oxide sensor fabrication in the form of a complete MEMS device, which could be used as a compact miniaturized surface mount devices package. Ceramic MEMS were fabricated by the laser micromilling of already pre-sintered monolithic materials. It has been demonstrated that it is possible to deposit metallization and sensor films by thick-film and thin-film methods on the manufactured ceramic product. The results of functional tests of such manufactured sensors are presented, demonstrating their full suitability for gas sensing application and indicating that the obtained parameters are at a level comparable to those of industrial produced sensors. Results of design and optimization principles of applied methods for micro- and nanosystems are discussed with regard to future, wider application in semiconductor gas sensors prototyping.

Semiconductor gas sensors detecting hydrogen peroxide

The results of studies of many types of semiconductor H2 O2 sensors are discussed in this review of 185 articles about hydrogen peroxide. The properties of electrochemical detectors, sensors based on organic and inorganic materials, graphene, and nano-sensors are analyzed. Optical and fluorescent sensors, detectors made of porous materials, quantum dots, fibers, and spheres are briefly discussed. The results of our studies in the YSU of hydrogen peroxide sensors made from solid solutions of carbon nanotubes with semiconducting metal oxides are also presented in the review. The fundamentals of the manufacture of biomarkers of respiration containing hydrogen peroxide vapors, which make it possible to judge the degree of a person's illness with various respiratory diseases (asthma, lung cancer, etc.), are discussed.

Creation of thin films on the surface of InP with a controlled gas-sensitive signal under the influence of PbO + Y2O3 compositions

Thin-film objects with a reproducible temperature dependence of the resistance, thermally stable, and easy to obtain can be used as the sensitive elements in semiconductor gas sensors. The aim of this study was to create thin films on the InP surface under the influence of an oxide chemostimulator + inert component (PbO + Y2O3, respectively) compositions and to determine their gas-sensitive properties and their dependence on the formula of the composition.Thin films were synthesised on the InP surface by the method of chemically stimulated thermal oxidation under the influence of various PbO + Y2O3 compositions. The thickness of the formed films, their elemental and chemical composition were determined (by laser ellipsometry, X-ray phase analysis, and infra-red spectroscopy). A number of experiments were carried out to establish the gas-sensitive properties of the obtained films with respect to ammonia with concentrations of 120, 100, and 80 ppm.By chemically stimulated thermal oxidation, we obtained thin films with semiconductor properties on the InP surface. It was determined that the samples had n-type conductivity. A gas-sensitive response was detected in the presence of ammonia in the atmosphere. The ability to create thin films with a predetermined value of sensory response was demonstrated

Strategies for Improving the Sensing Performance of Semiconductor Gas Sensors for High-Performance Formaldehyde Detection: A Review

Formaldehyde is a poisonous and harmful gas, which is ubiquitous in our daily life. Long-term exposure to formaldehyde harms human body functions; therefore, it is urgent to fabricate sensors for the real-time monitoring of formaldehyde concentrations. Metal oxide semiconductor (MOS) gas sensors is favored by researchers as a result of their low cost, simple operation and portability. In this paper, the mechanism of formaldehyde detection by gas sensors is introduced, and then the ways of ameliorating the response of gas sensors for formaldehyde detection in recent years are summarized. These methods include the control of the microstructure and morphology of sensing materials, the doping modification of matrix materials, the development of new semiconductor sensing materials, the outfield control strategy and the construction of the filter membrane. These five methods will provide a good prerequisite for the preparation of better performing formaldehyde gas sensors.

Measurement of Patchouli oil vapor using array of MOS gas sensors in various adulteration substances and concentrations

Indonesia is one of the main suppliers of Patchouli oil in the world market. It has high economical value. Indonesian Patchouli oil is mostly produced by SMEs using the distillation technique. However, the high demand and price of Patchouli oil led to the fraud of adulteration. SMEs intentionally mixed Patchouli oil with cheaper oils. This paper presented the vapor measurement of Patchouli oil by using an array of metal oxide semiconductor gas sensors (MOS) which may apply to indicate the presence of adulteration substance in Patchouli oil. A total of nine MOS gas sensors were tested. All MOS are driven with temperature modulation technique. We built an acquisition unit based on the PSoC device to acquire the MOS outputs to a computer. We tested two adulteration substances (palm oil and biodiesel oil), and two compositions (1:3 and 1:5) on two levels of Patchouli oil. Individual response of MOS was examined. The Principle Component Analysis (PCA) method was used to show the classification performance to distinguish the adulteration types in Patchouli oil. We found that there was no single MOS that able to distinguish the adulteration individually, and there were many overlapping responses to adulteration substances and compositions. The PCA results showed that on each level of Patchouli oil, nine MOS gas sensors can distinguish clearly between the with and without adulteration substances (palm oil and biodiesel oil).

An Ensemble Learning Method for Robot Electronic Nose with Active Perception

The electronic nose is the olfactory organ of the robot, which is composed of a large number of sensors to perceive the smell of objects through free diffusion. Traditionally, it is difficult to realize the active perception function, and it is difficult to meet the requirements of small size, low cost, and quick response that robots require. In order to address these issues, a novel electronic nose with active perception was designed and an ensemble learning method was proposed to distinguish the smell of different objects. An array of three MQ303 semiconductor gas sensors and an electrochemical sensor DART-2-Fe5 were used to construct the novel electronic nose, and the proposed ensemble learning method with four algorithms realized the active odor perception function. The experiment results verified that the accuracy of the active odor perception can reach more than 90%, even though it used 30% training data. The novel electronic nose with active perception based on the ensemble learning method can improve the efficiency and accuracy of odor data collection and olfactory perception.