Biomedical Engineering Reference
In-Depth Information
A summary of the piezoelectric sensors based on CNT gas-
sensitive layers are reported in the Table 9.7.
Table 9.7
Summary of the piezoelectric sensors using CNT active layer to
detect targeted gases
Target
analyte
Transducer
Materials/methods
Main performance
Ref.
SAW
315, 433 MHz
SWCNT/CdA
Nanocomposite LB film
at 27.5 wt.% filler
content
Ethanol,
Ethylacetate,
Toluene
CR: 1-180 ppm Ethanol
CR: 1-500 ppm Ethylacetate
CR: 1-150 ppm Toluene
DL: ~1 ppm; OT: RT;
Rst: <1 min; Rct: <10 min
[113]
SAW 433 MHz
QCM 10 MHz
SWCNT/CdA
Nanocomposite LB film
at 0-75 wt.% filler
content
Ethanol,
Ethylacetate,
Toluene
LIN: 0-200 ppm Ethanol
SSAW: 20 Hz/ppm (0 wt.%)
SSAW: 39 Hz/ppm (27.5%)
SSAW: 131.84 Hz/ppm (75%)
SQCM: 0.32 Hz/ppm (75%)
LIN: 0-150 ppm Toluene
SSAW: 144.7 Hz/ppm (75%)
[179]
SAW 69.3 MHz
Love mode
SWCNT/CdA
Nanocomposite LB film
at 75 wt.% filler content
H
, NH
, NO
2
CR: 0.030 - 1% H
[291]
2
3
2
CR: 30-1000 ppm NH
3
CR: 1-10 ppm NO
2
DL: <1 ppm
OT: RT; LIN: for All Gases
Rst: <1 min; Rct: <2-3 min
SAW 433 MHz SWCNT/CdA LB film
with purified SWCNTs
Alcohols
CR: 1-140 ppm Methanol
CR: 1-50 ppm Isopropanol
CR: 1-200 ppm Ethanol
LIN: for All Alcohols at RT
S increased with Oxid. CNTs
[186]
SAW 433 MHz
QCM 10 MHz
SWCNT LB film
multilayer onto
CdA buffer
VOCs
Mean Sensitivity QCM:
S: 3.46 Hz/mmHg Ethanol
S: 1.97 Hz/mmHg Methanol
S: 4.15 Hz/mmHg Isoproprop
S: 0.043 Hz/mmHg Acetone
S: 1.56 Hz/mmHg Ethylacet
S: 7.089 Hz/mmHg Toluene
Sensitivity SAW:
S: 43.7 Hz/ppm Toluene
[152]
SAW 433 MHz
Love mode
Spray CNTs layer with
as-grown CNTs
VOCs
Ethanol:
S: 6.89 kHz/ppm (SWCNTs)
S: 1.79 kHz/ppm (MWCNTs)
Ethylacetate:
S: 3.32 kHz/ppm (SWCNTs)
S: 0.90 kHz/ppm (mWNTs)
Toluene:
S: 3.17 kHz/ppm (SWCNTs)
S: 1.01 kHz/ppm (MWCNTs)
OT: RT
DL (SWCNTs): 1-3 ppm
DL(MWCNTs): 5-10 ppm
[112]
SAW
156 MHz
Spray MWCNT film
with purified CNTs
and functional groups
attached to CNTs
Ethanol
S: 9 kHz/ppm modified CNT
S: 5 kHz/ppm as-grown CNT
[293]
(
Continued
)
