Biomedical Engineering Reference
In-Depth Information
V
55 mm
Gas vent hole
PAN muscle
Anode (gold coated)
Cathode
Sodium chloride
solution
Rubber boots
Cap
FIGURE 4.49
Revised design of PAN muscle system (left) and a fabricated model (right).
FIGURE 4.50
Raw PAN fiber (left) and activated PAN fiber (right).
cathode were seemingly acting as an electric heat coil to boil the solution. It was
also found that significant damage of the electrode (anode) occurs due to electro-
chemical corrosion. The gold plate was slipped off, and the anode surface was eroded.
In this period, we were developing an improved gold-coating technique. Figure 4.51
depicts the electrical activation of active PAN fibers in an electrochemical cell subject
to 7 V. In order to collect baseline data and to arrange criteria of electrical activation
system design, we also carried out the PAN fiber contraction experiment in an acidic
solution (1
M
HCl; fig. 4.52).
From this experiment, we obtained 6-mm displacement that can be translated
into a generative force of 84
-gf
(= 0.82 N). This information gives rise to the fact
that the present system can produce an ultimate force of 0.82 N.
4.4
PAN pH METERS
PAN fibers were used for a variety of applications including pH meters (figs. 4.53,
4.54, 4.55, and 4.56). In figures 4.53 and 4.54, the fibrous polyacrylonitrile ionic
muscles contract and expand and turn a dial gauge to indicate the pH of a solution.
