Biomedical Engineering Reference
In-Depth Information
where
E
is Young's modulus,
I
is the moment of inertia, h is the thick-
ness,
w
is the width,
L
is the length,
is the density and the subscripts
np
and
p
denote the non-piezolayers and SU-8/ZnO piezo layer respec-
tively.
E
—
is given by,
Eh Eh
w Eh Eh EEhh h hh hp
+
1 2
np np
p p
=
()
(9.6)
24
24
2
2
EI
+
+
(4
+
6
+
4
)
np np
p p
np
p np p
np
np p
h e elastic modulus of SU-8/ZnO nanocomposite which was calculated
using the Hysitron Triboscope is 14 GPa.
h e fabricated cantilevers were tested for piezoelectric transduction
using a mechanical vibrator. Figure 9.22(a) shows the experimental setup
used for testing piezoelectric cantilevers. h e cantilever was mounted on
a shaker which acts as a vibration source to the cantilever. h e shaker was
Oscilloscope
DUT
Function
Generator
Shaker
(
a
)
160
60
30
120
0
80
-30
40
-60
0
1.0
1.5
2.0 2.5
Time (ms)
3.0
3.5
4.0
2
3
4
5
6
(
b
)
(
c
)
Frequency (kHz)
Figure 9.22
(a) Schematic of experimental setup (b) h e observed oscilloscope traces
of output voltage of the piezoelectric nanocomposite based MEMS cantilever during
periodic bending and unbending at resonance. (c) h e generated peak-peak voltage as
function of frequency of vibration.
