Biomedical Engineering Reference
In-Depth Information
as molecular platforms for the development of chemical sensors for
many applications and various environments.
At the current state, a broad possibility of combination between
gas-sensitive CNTs and transducers exists, thus an optimal selection
of the chemical sensor can be provided. However, the boundary
conditions for the sensor application determine the best practical
solution for a specific application. It is very difficult to give a definitive
statement on the highest sensor performance without considering
the real scenario for operation, because each CNT-based gas sensor
could match some given working conditions and mismatch other
operating situations. The final solution for the best CNTs chemical
sensor is strongly dependent on application and environment.
9.7
Challenges and Future Perspectives
The actual challenges in the field of the CNT gas sensors are the
controlled synthesis of the sensitive nanotubes with desired
properties at large scale for the fabrication of commercial chemical
nanosensors at high sensitivity, fast response and selectivity to
implement miniaturized, smart, and disposable devices for mass
production.
In this context, the synthesis of carbon nanomaterials with
selected area growth onto patterned substrates and their mani-
pulation for the integration into microdevices is currently addressed.
Great efforts in the controlled synthesis and surface modifications of
the sidewalls in the CNTs have been recently performed [312-318].
A hot topic connected to the synthesis of the CNTs is the
biocompatibility and toxicity of these carbon nanomaterials. Despite
a large research into fabrication, manipulation, integration, and
characterization of the CNTs, it is only recently that information on
toxicity and biocompatibility has become available. An interesting
review on the biocompatibility of CNTs is reported in literature
[319]. However, in the last few years, conflicting data have emerged
concerning the safety of CNTs. The results of these studies are often
inconclusive or contradictory. Clearly, these results urge caution
when handling CNTs, the usage of safety measures in manufacturing
facilities and laboratories should be seriously considered.
In general, CNTs offer several opportunities. First, CNT-based
devices can be assembled in a rational and designed manner due to a
