Page 134 - Organic Electronics in Sensors and Biotechnology

Strain and Pressure Sensors Based on OFET 111

FIGURE 3.19 Examples of sensorized garments for recording body signals.
(Reprinted with permission from Ref. 36. Copyright 2005, IEEE.)

track and a variation of its resistance. No spatial resolution is achiev-
able with such a strategy that is based on the measurement of the
resistance of the whole track.
Totally flexible organic field-effect sensors described in Sec. 3.3
can be integrated in different substrates to detect physiological
body parameters such as the joint movements, the breathing signal,
33
or the posture of a person. In Fig. 3.20 the sensor is glued on a
latex glove and positioned upon the joint between the first and the
middle phalanx of the index finger and used to detect the finger
movements.
As can be seen in Fig. 3.21, when the finger is clenched (tensile
stress on the transistor channel), the current decreases whereas when
the finger is forced to raise (compressive stress on the transistor
channel), the current increases as expected.

FIGURE 3.20 Organic fi eld-effect sensor glued on a latex glove and used to
detect fi nger bending movements.