Biomedical Engineering Reference
In-Depth Information
(B)
(A)
FIGURE 13.8
Optical micrographs of polypyrrole test lines: (A) 5 µm wide PPy lines and (B) 25 µm wide
PPy lines. The scale bars in both images represent a distance of 50 µm.
(A)
(B)
Measurement with optical microscope
Measurement of PPy expansion
with profilometer
Ag/AgCl REF
PPy WE
Pt CE
Pr
ofilometer stylus
Au CE
PPy WE
Stylus mov
ement
Polypyrrole
Au/Ti
Objective
NaDBS electrolyte
FIGURE 13.9
Experimental setup for the measurement of electrochemically controlled volume change of
polypyrrole test structures. (A) A profi lometer is used to measure the change in thickness of polypyrrole
electropolymerized on an Au/Ti line. (B) An inverted optical microscope is used to observe the profi le of a
polypyrrole test line, allowing measurement of the thickness change. WE, working electrode; CE, counter
electrode; REF, reference electrode.
WE and CE, with the same values as measured between WE and CE in the three-electrode setup
(0 V for oxidizing voltage,
−
2.5 V for reducing voltage). The inverted optical microscope allowed
the use of a larger volume electrolyte bath with three electrodes; however, the resolution of this
imaging was lower than that of the profi lometer. This low resolution was due to the relatively long
