Biomedical Engineering Reference
In-Depth Information
400
Sample #2
300
Sample #1 (baseline)
200
100
0
−
100
−
200
−
300
−
400
0
1
2
3
4
T (sec)
FIGURE 3.52
The current responses of IPMNC muscles (sample 1 vs. sample 2). A step
voltage of 2.2 V was applied.
particles via chemical plating, which uses reducing agents to load another phase of
conductive particles within the first layer. In turn, primary and secondary particles
can be secured within the ionic polymer network and reduce the potential intrinsic
contact resistances between large primary particles. Furthermore, electroplating can
be applied to integrate the entire primary and secondary conductive phases and serve
as another effective electrode (Shahinpoor and Kim, 2001e). The essence of such
physically loaded and interlocked electrodes for IPMNC is depicted in figure 3.53.
The principal idea of processing this new IPMNC so that primary and smaller
secondary particles can be secured within the polymer network has two parts:
First, physically load a conductive primary powder (Ag in this case) into the
polymer network forming a dispersed layer, which can function as a major
conductive medium near boundaries.
Subsequently, further secure such primary particulate medium within the
polymer network with smaller particles (Pd or Pt in this case) via a chemical
plating process.
Furthermore, an electroplating process can be applied to integrate the entire conductive
phase intact, serving as an effective electrode. Figure 3.53 illustrates such a process.
The processes developed are:
1.
A silver-based spherical powder (MOx-Doped Ag; Superior MicroPow-
ders EM10500X-003A; D
10
< 0.8
m; A
sur
< 6 m
2
/g) is dispersed in isopropyl alcohol (99%). Using a standard air
brush (VEGA), the powder is sprayed onto the backing material.
µ
m, D
50
< 1.5
µ
m, D
90
< 2.5
µ
2.
The isopropyl alcohol is then allowed to evaporate completely (it takes
approximately an hour).
