Controlled Fabrication of Nanostructure Material Based Chemical Sensors

Abstract

In this paper, we report on a processing approach for a microsensor platform that incorporates nanorods in a controlled, efficient, and effective manner. Using this novel approach of combining dielectrophoresis with standard microfabrication processing and materials, we have achieved reproducible, time-efficient fabrication of gas sensors with buried contacts to the tin oxide (SnO 2 ) nanorods used for the detection of gases. The steps associated with this approach are described in detail. Semiconducting SnO 2 nanorods are used to demonstrate this approach. The SnO 2 nanorods succeeded as sensing elements for the detection of hydrogen (H 2 ) and propylene (C 3 H 6 ) up to 600 o C, as well as the detection of nitrogen oxides (NO x ) at 400 o C. This investigation shows the combination of nanorods and standard microfabrication processing materials resulting in a new technique for the fabrication of chemical microsensors using nanomaterials.

Nanostructured material sensor processing using microfabrication techniques

“…The iron catalyst is removed from the MWCNTs by subsequent annealing at 1,7008C. This post-treatment also removes defects in the sidewalls of the tubes (Evans et al, 2010;Andrews et al, 1999). With loose surface carbon removed or returned to the ideal tube structure, the Figure 1 Dispersed MWCNT deposited on an interdigitated finger sensor structure (finger spacing , 10 mm) examined at lower and higher magnification (left and right hand side, respectively) Note: Notice the random, uncontrolled nature of the resulting deposition Source: Hunter et al (2006) MWCNTs have more uniform and reproducible exposed carbon planes and edges.…”