Artificial Perceptual Sensors - Artificial Human Sensors: Science and Applications - page 158

expected to be a natural part in the future kitchen, protecting people from drinking
unhealthy water. This attractive future perspective is especially sensitive for, small
children, elderly people or other individuals who are vulnerable to this type of
contamination.
As a safety concept, the tap water sensor experience provides an interesting
aspect of possible commercial introduction, e.g., the general electronic tongue con-
cept has been specifically fine-tuned towards the requirements of a taste sensor
system, which is able to detect small changes over time in the total quality aspect
of drinking water. The measurement procedure, when monitoring the quality of
the drinking water, uses the same principle (Fig. 6.17) as the previous simplified
device, as shown in Fig. 6.20. By using the technique of voltammetry (Fig. 6.18),
pulse cycles of different amplitude and an advance signal handling process, the
sensitivity can be increased and the discrimination between samples will substan-
tially be improved.
Depending on the chemical content in the drinking water samples in conjunc-
tion with a very sensitive method, it is always valuable to be aware of the tenden-
cies of variation that may occur and explain it to natural phenomenon or failure
to measure correctly. However, the sensing focus in this specific electronic tongue
concept, as shown below in Fig. 6.21, is typically based on a number of specifically
tested working electrodes, however, in this case only from gold and a platinum
material. This experience is due to acceptable response sensitivity and selectivity
received on drinking water experiments, and its behaviours when contaminated
by typically and expected chemicals or biological compounds. In connection to
the working electrodes, a reference electrode of stainless steel is, in these experi-
ments, needed to achieve a proper performance.

Figure 6.21. The electronic tongue prototype device mounted on the water tap. Photo

courtesy and copyright Peter Wide c 2010.