Biomedical Engineering Reference
In-Depth Information
PVDF Film
Load Cell
Figure 3.4
The material testing machine used for the characterization of mechanical properties
of PVDF films
Direction 2
Direction 1
30
20
10
0
0
0.5
Engineering strain (%)
1.0
1.5
Figure 3.5
Tested stress-strain characteristics for the uniaxial piezoelectric PVDF in direction 1
as well as direction 2
3.4.1 The Piezoelectric Properties of Uniaxial and Biaxial PVDF Films
The three piezoelectric coefficients,
d
31
,
d
32
,and
d
33
are of special interest in sensor
applications. The measurement of piezoelectric coefficients,
d
31
and
d
32
compared to
d
33
is straightforward and is explained below. Measurement of
d
33
is more complex and is
discussed separately in the next section.
