Year 2020: A Snapshot of the Last Progress in Flexible Printed Gas Sensors

A review of recent advances in flexible printed gas sensors is presented. During the last years, flexible electronics has started to offer new opportunities in terms of sensors features and their possible application fields. The advent of this technology has made sensors low-cost, thin, with a large sensing area, lightweight, wearable, flexible, and transparent. Such new characteristics have led to the development of new gas sensor devices. The paper makes some statistical remarks about the research and market of the sensors and makes a shot of the printing technologies, the flexible organic substrates, the functional materials, and the target gases related to the specific application areas. The conclusion is a short notice on perspectives in the field

Growth of ZnO tetrapods for gas sensor application

Zinc Oxide (ZnO) nanostructures have been obtained by vapour phase growth. Tetrapods have been grown in a reproducible way and separated from the other possible ZnO nano-morphologies, by the optimization of growth parameters. The further deposition of these nanostructures on an alumina substrate with contacts and heater, allowed us to test the gas sensing properties of the obtained ZnO tetrapods with different gases

Growth of ZnO tetrapods for gas sensor application

Zinc Oxide (ZnO) nanostructures have been obtained by vapour phase growth. Tetrapods have been grown on a large scale, in a reproducible way and separated from the other possible ZnO nano-morphologies, by the optimization of growth parameters. The deposition of these nanostructures on an alumina substrate with contacts and heater, allowed us to realize a low-cost oriented gas sensor. The obtained ZnO tetrapods-based gas sensor prototypes have been tested with different gases

Year 2020: A Snapshot of the Last Progress in Flexible Printed Gas Sensors

A review of recent advances in flexible printed gas sensors is presented. During the last years, flexible electronics has started to offer new opportunities in terms of sensors features and their possible application fields. The advent of this technology has made sensors low-cost, thin, with a large sensing area, lightweight, wearable, flexible, and transparent. Such new characteristics have led to the development of new gas sensor devices. The paper makes some statistical remarks about the research and market of the sensors and makes a shot of the printing technologies, the flexible organic substrates, the functional materials, and the target gases related to the specific application areas. The conclusion is a short notice on perspectives in the field

Spectroscopic–Electrical Combined Analysis to Assess the Conduction Mechanisms and the Performances of Metal Oxide Gas Sensors

Gas sensors that are based on metal oxides are extensively used to detect gaseous compounds in many different applications. One of the main tasks for improving the sensor performances is to understand the mechanism at the base of the sensing properties for each specific material. In this work, pure and mixed oxides were selected and synthesized in the form of nanometric powders. They were characterized by spectroscopic techniques, i.e., absorbance FT–IR and diffuse reflectance UV–Vis–NIR spectroscopies, to obtain information about the electronic properties and the type of defects that are involved at the root of the gas-sensing capabilities. The electrical characterization and the gas-sensing measurements were carried out on the related thick films. Finally, for each material, a description of the specific sensing mechanism is proposed by combining the characterization results

Deployment of new technologies for the abatement of atmospheric pollution and characterisation of health effects

Recent advancement in distributed architectures for tele-monitoring provides a significant spin-off to integrated new technologies that can address the aforementioned limitations and promote the use of accurate low-cost, electronic micro-sensors that also alleviate the administration headaches involved with changing state distributed networks. Today, it can be stated that micro-sensor technologies are mature instruments for measuring hazardous gases. These have been successfully embedded in small sensing terminals equipped with advanced communication tools and interfaces using existing mobile telecommunication networks, to enable the accurate temporal and spatial characterisation of atmospheric pollution and evaluation of potential health effects. Although we use atmospheric pollution as a specific example, this work is equally applicable in several areas of environmental pollution and aims to revise the current thinking of abatement strategies in Europe. It also endorses the adaptation of new tools that promote the use of extensive ICT networks and revolutionise the identification of hot-spots areas where health effects are greater. Data in the EU15 are shown for specific population groups (children between 0 and 4 years old etc) that are exposed to risks due to the vicinity of main roads at a distance up to 50m from each side of the road.JRC.H-Institute for Environment and Sustainability (Ispra

Physics and technology of thick film sensors and their applications for environmental gas monitoring

A nanostructured thick film gas sensor, based on semiconducting oxides, is an excellent candidate for a large-scale distribution of environmental detection points. Semiconducting oxide-based thick film gas sensors exhibit adequate properties for atm. environmental monitoring provided the phys. and microstructural properties of the materials are properly correlated to the required elec. features. To demonstrate the possibility of using semiconducting thick film gas sensors for atm. environmental monitoring, sensors were tested in the lab. and field. They were placed in an array inserted in a self-consistent unit and exposed to an actual atm. next to a conventional environmental monitoring station near a cross light in Ferrara, Italy. The conventional monitoring station is controlled by ARPA (Regional Agency for Environmental Prevention), Ferrara Section. The elec. response of the thick films based on TiO2 and Nb-doped TiO2 was compared to atm. CO concns. measured by the anal. equipments with methods approved by international stds

Spectroscopic–Electrical Combined Analysis to Assess the Conduction Mechanisms and the Performances of Metal Oxide Gas Sensors

Gas sensors that are based on metal oxides are extensively used to detect gaseous compounds in many different applications. One of the main tasks for improving the sensor performances is to understand the mechanism at the base of the sensing properties for each specific material. In this work, pure and mixed oxides were selected and synthesized in the form of nanometric powders. They were characterized by spectroscopic techniques, i.e., absorbance FT–IR and diffuse reflectance UV–Vis–NIR spectroscopies, to obtain information about the electronic properties and the type of defects that are involved at the root of the gas-sensing capabilities. The electrical characterization and the gas-sensing measurements were carried out on the related thick films. Finally, for each material, a description of the specific sensing mechanism is proposed by combining the characterization results

Nanostructured chemoresistive thick film gas sensors: theoretical and technological aspects

This work is aimed to examine nano-ceramic metal-oxide semiconductors and their peculiar features devoted to gas sensing application, particularly in the atmospheric pollutants monitoring. For this purpose, sensors have to measure traces of gases in the atmosphere with sensitivity and selectivity comparable to those of the analytical devices; moreover it is necessary for them to be stable, repetitive and reliable. For sensor engineering, further improvements in research and technology are needed, especially a deeper understanding of the physics and, more specifically, of the change in the characteristics due to the nanometric size. Indeed, the characteristic length below which a material can be properly considered as nanosized is a parameter of great significance in gas detection

Printed semiconducting gas sensors

Whilst printed films are currently used in varied devices across a wide range of fields, research into their development and properties is increasingly uncovering even greater potential. Printed films provides comprehensive coverage of the most significant recent developments in printed films and their applications. Materials and properties of printed films are the focus of part one, beginning with a review of the concepts, technologies and materials involved in their production and use. Printed films as electrical components and silicon metallization for solar cells are discussed, as are conduction mechanisms in printed film resistors, and thick films in packaging and microelectronics. Part two goes on to review the varied applications of printed films in devices. Printed resistive sensors are considered, as is the role of printed films in capacitive, piezoelectric and pyroelectric sensors, mechanical micro-systems and gas sensors. The applications of printed films in biosensors, actuators, heater elements, varistors and polymer solar cells are then explored, followed by a review of screen printing for the fabrication of solid oxide fuel cells, and laser printed micro- and meso-scale power generating devices