Biomedical Engineering Reference
In-Depth Information
Three PAN muscles of 30-strand fiber bundles were further tested under 3, 5,
and 7 V. One PAN muscle bundle with the same number of strands was tested under
5 V with polarity change. The polarity was changed every 5 min. Sodium chloride
solution was stirred for 1 min in order to compensate the ion concentration difference
near both the anode and cathode sides. This is thought to delay the contraction and
elongation of the PAN muscle.
Dehydration of PAN muscle was observed on each fiber after the said operation.
It is generally believed that it affects the mechanical property of PAN muscle and
weakens the strength of the PAN fibers. The length of samples 1 and 2 was
measured, but sample 3 was damaged during such measurements. It was assumed
that the displacement of sample 3 was comparable with the displacements of
samples 1 and 2. It was further assumed that the displacement of these samples is
linearly related to force increase. Both samples contracted 5 mm after 20 min of
operation. Figures 4.111 and 4.112 show length changes of such PAN muscle
samples. Note that the electrically induced contraction was more pronounced in the
lateral dimensions than the longitudinal direction.
Single fiber force curve (5 V)
12
10
8
6
4
2
0
0
200
400
600
800
Time (sec)
FIGURE 4.110
Single fiber force curve under 5-V electric field.
FIGURE 4.111
PAN fiber length (before test: 170 mm [left]; after test 165 mm [right]),
under 5 V.
