Detection of gases with arrays of micromachined tin oxide gas sensors

Direct synthesis of tin oxide nanotubes on microhotplates using carbon nanotubes as templates

“…mechanism for tin oxide gas sensors generally produces devices that have good sensitivity, but limited chemical selectivity, because many reducing species can act to displace the adsorbed oxygen. Chemical selectivity is achieved through additional use of catalyst layers, [33][34][35][36][37][38] selection of operating temperatures in arrays, 39,40 and temperature programmed sensing. 41 For temperature programming, the reduced resistance of the NT-based structure, compared to NP sensing materials, is advantageous.…”

SOI CMOS Compatible Low-Power Microheater Optimization for the Fabrication of Smart Gas Sensors

“…To compensate this lack of uniformity, the literature [10], [13]- [16] often introduces either a silicon heat spreader under the active area, or a thermal conductive layer (e.g., aluminum) over the structure, but these solutions lead to higher thermal inertia and consumption. In our proposed gas sensor application, the membrane is only covered with high thermal conductivity gas sensitive layer (metallic-oxide layer like SnO or WO ) to increase the conductivity and also the uniformity inside the heater perimeter without increasing the power consumption (Fig.…”

Use of boron heavily doped silicon slabs for gas sensors based on free-standing membranes

“…For instance micromachined hotplates are used in chemical gas sensors for actively heating a sensitive material [1][2][3] and micromachined thermopiles are used as infrared detectors in optical gas sensing systems [4][5][6][7]. Bulk micromachined hotplates and thermopiles share several common features and, in fact, the same technology enables the fabrication of both devices.…”