Biomedical Engineering Reference
In-Depth Information
350
300
250
200
150
100
50
0
-50
0
2000
4000
6000
8000
10000
Time (ms)
(a) Loading waveform
1.5
1.0
0.5
0.0
-0.5
-1.0
-1.5
0
2000
4000
6000
8000
10000
Time (ms)
(b) Piezo-voltage waveform
FIGURE 9.16
Loading and piezovoltage waveforms.
9.5.3 Discussion
The results in the preceding section indicate that in the case of three-point
bending, the signs of the piezovoltage at electrodes 1-1′ ~ 3-3′ were oppo-
site to those at electrodes 4-4′ ~ 6-6′, and the signs at electrodes 7-7′ ~ 8-8′
of the type B sample were the same as those at electrodes 1-1′ ~ 3-3′ of
the type A samples. In the case of four-point bending, the piezovoltages
of all the electrodes of the type A samples and electrode 8-8′ of the type B
