Biomedical Engineering Reference
In-Depth Information
FIGURE 4.142(b)
Right side view of PAN five-fingered hand.
PAN fiber bundles' (of 50 fibers) typical contraction of more than 100% is shown
in figures 4.145a, 4.145b, and 4.145c.
4.8
MICRO-PAN FIBER OBSERVATION
Figure 4.146 shows the volume change of minute PAN fibers. Marked fibers in the
circle mean the same fiber, which elongates and contracts under basic and acidic
solution. In elongation status, the length and the diameter of the fiber were 350 and
40
µ
m, respectively. In contraction status, they were constricted to 120 and 14
µ
m,
respectively.
After simple calculation, the volume of the minute PAN fibers was measured to
be 4.0
10
-5
mm
3
in contracting state. The
volume change ratio (swelling status/contracting status) is about 2380%.
It was determined from a previous experiment that a single fiber can generate 5
gf under 1
M
HCl solution. If we assume that a single fiber has about 2,000 ~ 2,500
minute fibers and each fiber equally contributes to force generation, a minute fiber
generates 2.0 ~ 2.5
×
10
-4
mm
3
in swelling state and 1.8
×
10
-3
gf. Observing volume change of the minute PAN fiber
under applied electric field is also under consideration.
×
4.9
CONCLUSIONS
Described in this chapter are results obtained over a period of eight years on
electroactive polyacrylonitrile (PAN) as well as a model and experimental results
that allow one to electrically control the actuation of active conductive PAN fiber
bundles, or C-PAN. Increasing the conductivity of PAN fibers by making a composite
of them with a conductive medium such as platinum, gold, graphite, or carbon
nanotubes and conductive polymers such as polyaniline or polypyrrole has allowed
for electric activation of PAN fibers when a (C-PAN) fiber bundle is placed in an
