Microfabrication of flexible gas sensing devices based on nanostructured semiconducting metal oxides

Nanoscale Heterostructures Based on Fe2O3@WO3-x Nanoneedles and Their Direct Integration into Flexible Transducing Platforms for Toluene Sensing

“…45 The sensors were exposed to the analytes for 10 min and subsequently the chamber was purged with air until initial baseline resistance was recovered. The whole testing period comprised 100 h during which sensors were tested to the analytes at various operating temperatures (100, 130, 160, 190, 220, and 250°C) performing up to four replicates for each condition (i.e., analyte, operating temperatures, and analyte concentrations).…”

Chemical Vapour Deposition of Gas Sensitive Metal Oxides

“…These materials are typically monoclinic or tetragonal phases with a variety of morphologies reported including films, particles and low dimensional structures, with the formation of nanostructures (NS) demonstrated below 600˝C for AACVD [15] and at 800˝C for hot filament CVD. The starting materials reported in the production of gas sensitive tungsten oxide include metallic W [16,17], WO 3 (powder, pellet) [18,19], WCl 6 [20], W(OCl 4 ) [21], W(CO) 6 [22][23][24] [20,21,26,27], silicon- [16,22,23,25] or polymer-based [28] gas sensing devices. The localized CVD of tungsten oxide nanostructures on Si-based microhotplates ( Figure 1) via heating provided from the sensor platform itself, rather than from the reactor chamber, has also been demonstrated as a viable method for the fabrication of gas sensors based on tungsten oxide [23], which provides interesting new possibilities for sensor processing.…”

“…CVD has also been demonstrated to simplify sensor processing by providing direct integration of tungsten oxide sensor materials with the sensor platform. This has been demonstrated particularly for aerosol assisted CVD, which has shown the selective deposition of networked or quasi-aligned tungsten oxide NS on ceramic- [33], silicon- [32] and polymer-based platforms [28].…”

TiO2 Nanotubes Membrane Flexible Sensor for Low-Temperature H2S Detection

“…These devices require new features such as low-power consumption, low-cost and low-weight in addition than good sensitivity, selectivity and stability. In particular, the use of substrates flexible for manufacturing gas sensors could be a potential alternative to the more expensive silicon technology [13][14][15][16].…”