Biomedical Engineering Reference
In-Depth Information
2.
Plating amount is determined by the content of Pt in the solution. Prepare
a 5% aqueous solution of hydroxylamine hydrochloride and a 20% solu-
tion of hydrazine monohydrate.
3.
C. Add 6 ml of the
hydroxylamine hydrochloride solution and 3 ml of the hydrazine solution
every 30 min. In the sequence of addition, raise the temperature up to
60
Place the polymer in the stirring Pt solution at 40
°
C gradually for 4 h. Note that gray metallic layers will form on the
membrane surface. At the end of this process, sample a small amount of
the solution and boil it with the strong reducing agent (NaBH
4
) to check
the end point.
°
Other metals (or conducting media) that are also successfully used include
palladium, silver, gold, carbon, graphite, and carbon nanotubes (see fig. 3.13). Also,
it is noteworthy that the use of electroplating was found to be very convenient (Kim
and Shahinpoor, 2003).
3.3.3
F
ORCE
O
PTIMIZATION
The fabricated IPMNCs can be optimized for producing a maximum force density
by changing multiple process parameters, including bath temperature (
T
R
), time-
dependent concentrations of the metal containing salt,
C
s
(
t
), and the reducing
agents,
C
R
(
t
). The Taguchi design of experiment technique was conducted to
identify the optimum process parameters (Peace, 1993). The analysis techniques
for “larger-the-better” quality characteristics incorporate noise factors into an
experiment involving “larger-the-better” characteristics, for the maximum force
generated by the manufactured IPMNCs in this case. Such an analysis allows us
to determine the key factors and the possible best settings for consistently good
performance. The beauty of this technique is just as applicable for attaining
consistently high “larger-the-better” responses for process performance and end
product functionality (Peace). In table 3.4, experimental design and signal-to-noise
(S/N) ratio data are provided.
500
µ
m
FIGURE 3.13
A cross-section of an IPMNC showing two electrodes (top and bottom) with
porous expanded graphite and dense platinum. This IPMNC is manufactured by the solution-
casting and further treatment with porous graphite and chemical reduction of platinum as
effective compliant electrodes.
