Biomedical Engineering Reference
In-Depth Information
8
Step input, 1/2 Hz
Sample-C(Pt)
Sample-B(Pt)
Sample-A(Pl)
6
4
2
0
0.0
0.5
1.0
1.5
2.0
2.5
E
app
(V)
FIGURE 3.33
Change in blocking force for typical samples after stretching.
8
Step input, 1/2 Hz
7
Sample-C (Pt/Au)
Sample-B (Pt/Au)
Sample-A (Pt/Au)
6
5
4
3
2
1
0
0.0
0.5
1.0
1.5
2.0
2.5
E
app
(V)
FIGURE 3.34
Change in blocking force for typical samples after stretching. The force is
increased by a factor of almost two.
The change in blocking force is rather significant, as shown in figure 3.33.
Figures 3.33 and 3.34 show the measured blocking forces as a function of electric
potential imposed across the IPMNCs. Overall, the blocking forces are fairly large
(up to 10 gram force [gf]) for sinusoidal and step inputs at 0.5 Hz. Note that the
effective length was set at 12.7 mm.
Figures 3.35 and 3.36 depict additional results for blocking force increase upon
IPMNC stretching. Figures 3.37 through 3.40 depict scanning electron micrographs (SEM)
of stretched IPMNC samples. Figure 3.41 depicts the sequential increase in blocking force
upon adding dispersant polyvinyl pyrolidone (PVP) and further stretching to 19%.
It appears that much higher forces can be obtained. As can be seen, stretching
probably induced larger void volume so as to increase the permeability significantly.
As a result, platinum particles are well distributed within the electrodes near bound-
aries of IPMNCs. These new developments are being further investigated.
