Biomedical Engineering Reference
In-Depth Information
110
100
90
Contraction
80
Elongation
70
60
50
40
30
0
2
4
6
8
10
12
14
16
18
20
Time (min)
FIGURE 4.74
Electrical activation of C-PAN made with single PAN graphite fibers of 2,000
strands.
Electrical activation of PAN-graphite (1:2 ratio) muscle
7.00
6.00
5.00
4.00
3.00
2.00
1.00
0.00
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
Time (sec)
FIGURE 4.75
Variation of length of C-PAN-G strands of 10 µm in diameter with time in a 0.2-
m
N
NaCl cell under a voltage of 20 V (1PAN-2G ratio in a special helically wound configuration).
thick. These nanosize cross-bridges, which are attached to the thin filament, swing
and then detach in the presence of ATP, being ready for the next cycle. Such a
mechanism is truly based upon a chemomechanical nanoscale motion that can
ultimately cause biological muscle to contract in a collective manner to achieve
macroscaled motions with useful forces. Inspired by the fact that extremely fast
response times can be attained by hierarchically moving towards smaller and smaller
diameter fibers, just like the biological muscles, nanofibers of PAN were manufac-
tured by electrospinning.
Conventional PAN fibers that are commercially available (Orlon) are shown in
figure 4.76. Normally, they are composed of 2,000 strands or microfibrils of 10
m
in diameter. They are used vastly for textile applications and in fact are known as
artificial silk.
µ
