Electronic Nose Based on Nanomaterials: Issues, Challenges, and Prospects

Figure 7

SEM image of the EN device showing the wire-bonding pads, which connect SnO₂ NWs. A meander heater is incorporated into the chip at the bottom producing a 240–285°C temperature gradient in the vertical direction. SEM images of representative NWs (pristine, Pd-decorated, and Ag-decorated) are also shown as insets, as well as lower magnification images of the NWs (right-hand side) to show the manner in which they contact the pads. The scale bars are 10 nm. The sensitivity of the individual sensors towards H₂, CO, and C₂H₄ measured at 270°C in a stream of flowing air (10 sccm). Published with permission from Baik et al. [106], Copyright © 2012 American Chemical Society.