Biomedical Engineering Reference
In-Depth Information
(4.5)
E
=
300
20
πσ
r
4
σ
(4.6)
E
=
0 863
.
er
o
Inspection of recast equations (4.4) and (4.5) reveals the dimensionless critical
voltage,
E
h
,
er
e
/
σ
to be constant or a function only of the geometric ratio (
h
/
r
) with a power-law
exponent of 0.5 or 1.
4.6.8
F
ABRICATION
OF
A
PAN A
CTUATOR
S
YSTEM
The configuration in figure 4.85 shows the fabricated PAN actuator system. The
dimension is provided. It can cause the PAN fiber to contract within the flexible
membrane (rubber boots). Once the polarity is changed, the PAN fiber tends to
expand and the compressed flexible membrane will help it expand in a resilient
manner. The fabrication of this unit has been completed and is now ready for
performance testing. The test results will be reported in the near future.
Note in figure 4.85 that first we measured the spring constant of the rubber boots
by applying predetermined loads. The measurement gave the spring constant of
k
=
0.01 kg/mm. Inside rubber boots, as can be seen, the following components are
positioned: the PAN muscle bundle, electrodes, and a solution. Applying electrical
currents through the electrodes can perform the system operation. The inner electrode
(a circular shape) surrounds the PAN muscle bundle and the other is attached to the
boots' wall. The clearance between the boots' wall and the inner electrode is approx-
imately 15 mm.
V
Gas vent hole
PAN muscle
We ak spring form
of electrode
∅
38 mm
Water
Rubber boots
Cap
FIGURE 4.85
A PAN actuator system.
