Chemical Analysis of Nano-structures for Toxic Gas Detection
EMSL Project ID
9796
Abstract
New chemical agent detectors for toxic and explosive gases are of high current interest due to new requirements for homeland security. The most common technology for detecting many of these gases involves measuring the resistance change of metal-oxide films such as SnO2 or ZnO2 caused by gas exposure. These films are typically fabricated from thick-film pastes or by thin-film techniques such as evaporation or sputtering. The sensors that use these films are large and relatively expensive, have poor selectivity and high power consumption, and can be poisoned when exposed to other gases. Nanotechnology offers a newer fabrication approach that has the potential for making nano-structures as sensing elements that are extremely small, with new and unexpected physical or chemical properties for next generation sensing technology. The overall objective of this research project is to investigate feasibility of using electric-field-enhanced nano-oxidation as a nano-fabrication technique to synthesize nano-structures for next generation hazardous gas sensing devices. The use of this technique for the fabrication of sensing nano-structures is innovative since there have been no reports of this in the literature. If successful, this work will be a significant advancement since these nano-devices may have novel properties that could improve the selectivity, sensitivity and stability of sensing devices, while dramatically reducing size and cost. Project tasks that are completed include establishing the relationship between write speed, tip force, and relative humidity on nano-structure reproducibility and yield; and determining the optimum etch time for the nano-oxide structure release process. The objective of this EMSL user facility project is to obtain a chemical analysis of the nanostructures using Auger, XPS or EDX to insure that the structures grown are truly the metal oxide desired without contaminants from the AFM tip. Stoichiometric information would also be useful along with an SEM image of the nanostructures for comparison with AFM images.
Project Details
Project type
Exploratory Research
Start Date
2004-07-01
End Date
2006-04-10
Status
Closed
Released Data Link
Team
Principal Investigator