Biomedical Engineering Reference
In-Depth Information
30
25
20
15
10
PVP treated
PVP untreated
5
0
0
10
20
30
40
50
60
Frequency (Hz)
FIGURE 3.62
Thermodynamic efficiency of the IPMNC as a function of frequency.
The samples used in figure 3.62 have a dimension of a 20-mm length, 5-mm
width, and 0.2-mm thickness. The applied potential is 1-V step. Lines are least-
square fits. Resonant efficiencies are not included in this figure. It appears that, at
higher frequencies, the thermodynamic efficiency stabilizes and almost remains the
same. This phenomenon, as well as the resonance state efficiencies, is currently
under investigation.
3.3.10 T
ECHNIQUE
OF
M
AKING
H
ETEROGENEOUS
IPMNC
C
OMPOSITES
Platinum is not the only noble metal that can be produced by chemical reduction
processes. Other noble metals such as palladium, gold, and silver have been tried.
Although there are not enough data at the present time regarding those noble metals
as effective materials used to place electrodes on IPMNC samples, there are enough
indications that they are also effective. Also, a heterogeneous technique of manu-
facturing the nanocomposites of IPMNCs, such as an alternative placing the Pt
composite first, palladium next, then again platinum and, subsequently, palladium,
etc., have been tried to control the penetration depth. Overall, those laminating
procedures to make laminated nanocomposites of IPMNCs appeared to be very
promising and effective.
Another interesting technique is to combine conducting polymers (polypyrrole)
and metals so as to create a system of the base polymer/metal/conducting polymer.
We have fabricated such an IPMNC system. One finding was that this procedure
significantly reduced the input power consumption while maintaining the same level
of the generative blocking forces. Such an effect could be attributed to less I/V
hysteresis acting on the metal particle interacting surfaces. The results are briefly
presented in figure 3.63.
