Biomedical Engineering Reference
In-Depth Information
Ω
gate voltage is ~360 k
. Miniaturized gas sensors using individual
SWCNTs are thus demonstrated.
Figure 9.9
Changes of electrical characteristics of a semiconducting
SWCNTs in chemical environment. (a) AFM image of a SWCNTs
sample used for gas sensing experiments. Nanotube diameter
is about 1.8 nm. The metal electrodes consist of 20 nm thick Ni,
with 60 nm thick Au on top. (b) Current versus voltage curves
recorded before and after exposure to NH
(c) Current versus
voltage curves recorded under a gate voltage,
3.
V
= +4 V, before
g
and after NO
exposure. (Reprinted with permission from
2
Science
[33].)
Figure 9.10
The nanotube gas ionization sensor. (a) Exploded view of
sensor showing MWCNT film as anode, 180-
m thick glass
insulator plates, and Al plate as cathode. (b) Scheme of test
set-up. (c) SEM image of the CVD-grown vertically-aligned
MWCNT film used as anode. Reprinted with permission from
Nature
µ
[148].
