Artificial Perceptual Sensors - Artificial Human Sensors: Science and Applications - page 138

Figure 6.6. An electronic nose system mounted on a mobile robot, comprising of two
“nostrils”. Photo courtesy and copyright Peter Wide c 2010.
also named electronic smell sensors, cannot be fairly compared when an artificial
system containing 20 to 100 sensor elements in comparison with a human capabil-
ity of estimated 10 million olfaction receptor cells. The number of receptor cells in
a dog's nose may be even more, perhaps 20 times, compared to a human olfaction
organ, Schiffman (1996).
In Fig. 6.6, an illustrative example, Loutfi (2004), is demonstrated. A mobile
robot is controlled by the input from two nostrils as built in a compact sensor sys-
tem. The benefits, as seen in the figure above, can be achieved in the phase detec-
tion of airborne molecules that can detect the flow of air-driven compounds. This
type of applications may be directed towards identification and localisation of air-
borne compounds in order to find the source of contamination, e.g., monitoring of
volatile compounds emitted from food packaging board products, Forsgren (1999).
A thorough overview of olfaction-based sensors is provided in Pearce (2003). Also
a more extensive overview of artificial olfaction systems can be found in, Loutfi
(2002), Deisingh (2004), and Perera (2002).
6.3.2 Gustatory Sensors
Conceptually, the electrochemistry-based sensors are focussed on the chemical
response of the applied electrical signals, Wang (1994). Liquid related applications
have been inspired by sensor technologies mainly based on conductivity, Chen
(2005), polymer films, Guo (2005), potentiometry, Legin (2004) or voltammetry,
Winquist (1997).
The principal technique of the taste sensor presented in this topic is based on