Amperometric gas sensors based on screen printed electrodes with porous ceramic substrates

Amperometric Hydrogen Sensor Based on Solid Polymer Electrolyte and Titanium Foam Electrode

“…In our previous work, the large porosity of the porous ceramic was used as the substrate and the Pt SPE has a rough surface, , which results in a small three-phase interfacial area between the smooth solid polymer electrolyte membrane and WE. The Pt electrode layer with a thickness of 10 μm was formed, which led to a waste of precious metal.…”

“…The difference is to use a porous ceramic substrate as the gas diffusion barrier to improve the sensor design as pointed out in our previous study. 21 The gas molecules directly diffuse from the porous substrate to the three-phase interface without passing through the electrolyte membrane, which effectively improves the response speed of the device. Besides, since the interface between the electrolyte membrane and the electrode is a two-dimensional planar structure, the area of the effective three-phase interface is small, which limits the sensitivity of the hydrogen sensors.…”

“…However, conventional electrode structures based on solid ceramic substrates have limited gas diffusion rates because gas needs to dissolve and diffuse in RTIL before reaching the three-phase interface. The difference is to use a porous ceramic substrate as the gas diffusion barrier to improve the sensor design as pointed out in our previous study . The gas molecules directly diffuse from the porous substrate to the three-phase interface without passing through the electrolyte membrane, which effectively improves the response speed of the device.…”

Challenges and Opportunities for Printed Electrical Gas Sensors

“…While organic substrates can be flexible or rigid depending on the chemistry and formulation used, inorganic materials, such as ceramics, are primarily used as rigid substrates. , Though low-cost and compatible with various large-volume production methods such as roll-to-roll printing, organic substrates are not compatible with fabrication and operating sensing regimes that require high temperatures. For example, polyethylene terephthalate (PET), a common substrate used in the fabrication of printed devices, has a glass transition temperature of below 150 °C whereas many inks employed in screen and inkjet printing need higher temperature for the curing process. , Additionally, numerous gas sensors require high temperatures (>200 °C) to operate due to the inherent nature of their sensing materials (for example, metal oxides) , or their application (for example, automotive industry, agriculture waste processes, nuclear power plants, aerospace industry). , Inorganic substrates such as ceramics − and silicon derivatives , have been traditionally used because of their compatibility with high temperatures and resistance to harsh environments. With the rise of wearables and smart packaging labels, however, there is increasing interest in the use of flexible and stretchable substrates for the fabrication of printed electrical gas sensors. − Extensive research is currently dedicated to improve thermal properties of flexible materials and to lower curing and operation temperatures of printable inks to enable the integration of printed gas sensors into those applications. − Because of potential contact with skin and food, biocompatibility and toxicity have become important criteria in addition to the mechanical properties of the substrates .…”

Tunable Size of Hierarchically Porous Alumina Ceramics Based on DIW 3D Printing Supramolecular Gel

“…Therefore, it is also a big challenge for DIW 3D printing hierarchical porous ceramics with precisely tunable size. In addition, owing to their high porosity, high specific surface area, low density, and good heat resistance, hierarchically porous alumina ceramic foams are expected to be applied in high-temperature thermal insulation, , tissue scaffolds, catalyst supports, and electrodes. , However, until now, the application of DIW 3D-printed hierarchically porous alumina ceramic foams has not been thoroughly evaluated and investigated.…”