Biomedical Engineering Reference
In-Depth Information
variation in the magnitude of the frequency response is modulated
by acoustoelectric effect. In fact, the increasing in the electrical
conductance (electron density) of the LB nanocomposite can
significantly contribute to enhanced SAW vapor sensitivity due to
improved acoustoelectric interaction between free charge carriers
of the LB nanocomposite and the electrical field associated to SAW
propagating along coated acoustic sensing device. In particular,
the highest response caused by the LB nanocomposite with filler
of oxidized SWCNTs (OX-SWCNTs) is due to the highest electron
density introduced in the SWCNTs filler by the purification of the
oxidation process.
(a)
(b)
(c)
Figure 9.23
(a) Room temperature transient response of a SAW 433 MHz
sensor coated with a 2-monolayer LB 75 wt.% nanocomposite
film with three different SWCNTs fillers, and exposed to
three concentrations of methanol. (b) Calibration curves
to methanol for a SAW 433 MHz sensor coated with three
2-monolayer LB 75 wt.% nanocomposite film with different
SWCNTs fillers, at room temperature. (c) Chemical patterns
of room-temperature sensitivity to three alcohols using a
SAW 433 MHz sensor with three different 2-monolayer LB
75 wt.% nanocomposite film. This figure is reprinted and
adapted with permission from IOP [186].
We observe further that this tailored sensitivity of raw and puri-
fied SWCNT-based LB nanocomposites is also ranked in the whole
