Biomedical Engineering Reference
In-Depth Information
performance testing. The instrumentation has been completed. Note that a leak-tight
system is important.
First, we measured spring constant of the rubber boots by applying predeter-
mined loads. The measurement gave the spring constant of
k
= 0.01 kg/mm. Inside
the rubber boots the following components were positioned as can be seen: the PAN
muscle bundle (0.2 g, 15 strains), 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.
PAN fibers were cooked at 220
C for 90 min and boiled in 1
M
LiOH for 30
min based upon the recent finding that LiOH boiling gives better performance in
terms of elongation/contraction (fig. 4.46). The PAN fiber bundles were looped. The
PAN muscle bundle (fig. 4.47) was placed between the top and bottom caps. PAN
fibers were hung up from both hooks of the cap, then immersed into the water filling
the insides of the rubber boots as shown in figure 4.48.
°
4.3.12
PAN C
ASTING
E
XPERIMENT
We were able to have a thin 1-mm PAN sheet activated (high pH activation). Further,
they tried to composite PAN/Pt via ion-exchange processes and a metal reduction
process [Pt(II)
Pt(0)]. It appears that the Pt reduction is fast so that Pt particles
precipitate in solution rather than inside PAN (fast kinetics). Further study is now
under way to understand this process.
→
FIGURE 4.46
Annealed (cross-linked) PAN fibers.
FIGURE 4.47
Looped PAN fiber bundle.
