Integration of one-dimensional gas sensitive nanostructures grown via chemical vapor deposition into microdevices

abstract

English

Nanostructures (NS), e.g., based on metal oxides, are attractive in gas sensors because they proved to enhance the functionality of these devices, providing better sensitivity, stability, and selectivity. Further enhancement of the functionality of nanostructures is also known to be achieved by electronic and/or chemical sensitization via the surface modification with second-phase materials (e.g., catalytic nanoparticles with sizes less than 10 nm). The formation of NSs is traditionally achieved via liquid- or vapor-phase routes, with the vaporphase routes (e.g., CVD) having shown advantages that include greater purity, the ability to generate NSs in continuous rather than batch mode and higher throughputs. Thus, in this work, we will discuss the use of CVD and aerosol assisted (AA) CVD to synthesize nonmodified and modified NSs, demonstrating that the selective synthesis of NSs, their functionalization and their integration into silicon- or polymer-based microsystems can take place in a single processing step. Additionally, we will show the feasibility of using resistive heaters embedded in microdevices to perform CVD of NSs, and the integration of NSs into nanoelectrode arrays systems by dielectrophoresis, as a strategy to achieve a well-defined conduction channel easy to modulate by external stimuli (e.g, gaseous molecules) in chemoresistive sensors. Comparative results of the functionality of these devices as function of the integration methods employed will also be presented.

Gas sensors, AACVD,k nanostructures, nanoelectrode

VALLEJOS VARGAS, S.; GRÁCIA, I.; FIGUERAS, E.; CHMELA, O.; DOMÈNECH-GIL, G.; PRADES, D.; HUBÁLEK, J.; ROMANO-RODRÍGUEZ, A.; CANÉ, C.

12. 4. 2018

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