ABSTRACT
This chapter describes how chemiresistive gas sensors can benefit from aerosol-based techniques—and in particular from nanoparticle synthesis by spark ablation—for synthesizing the sensing materials. A gas flow passing through the gap between the electrodes serves for quenching the resulting vapor clouds, which subsequently condense to form atomic clusters and nanoparticles while being carried out of the discharge chamber. The chapter provides an overview of the operating principles of chemiresistors that employ metal oxide or metallic nanoparticles and highlights the unique features of spark ablation that can attribute desired properties to the building-block nanoparticles and the end sensing nanomaterials. Nanoparticle synthesis by spark ablation, coupled with state-of-the-art deposition methods offered by aerosol-based techniques, provides high flexibility in synthesizing nanostructured chemiresistors of well-defined properties. The chapter discusses the advantages of using the techniques described for synthesizing materials for environmental gas sensors. Electric discharges have been used to produce gas-suspended nanoparticles since the 1980s.
