Biomedical Engineering Reference
In-Depth Information
IPMC response under
compression (200N load)
250
250
Sensor output
Load
200
200
150
150
100
100
50
50
0
0
-50
-50
0 0 0 0 0
Time (s)
50
60
70
80
FIGURE 7.18
Outvoltage due to normal impact of 200-N load on a 2-cm
×
2-cm
×
0.2-mm
IPMNC sample.
L
x
v
FIGURE 7.19
IPMNC cantilever beam.
and exhibit low impedance. They have been modeled as capacitive and resistive
element actuators that behave like biological muscles and provide an attractive means
of actuation as artificial muscles for biomechanic and biomimetic applications.
Essentially, the polyelectrolyte membrane inside the composite possesses ionizable
groups on its molecular backbone. These groups have the property of disassociating
and attaining a net charge in a variety of solvent media. In particular, if the interstitial
space of a polyelectrolyte network is filled with liquid containing ions, then the
electrophoretic migration of those ions inside the structure due to an imposed electric
field can cause the macromolecular network to deform accordingly.
7.4.2
S
TATIC
D
EFLECTION
The ionoelastic beam is depicted as an elastic cantilever beam, shown in figure 7.19.
The nonlinear equation for large-angle deflections in elastic cantilever beams is
2
∂
∂
()
v
M
EI
2
x
=−
(7.7)
32
/
2
∂
∂
v
x
1
+
