Multi-furcation assembly of charged aerosols and its application to gas sensing

Abstract

In this thesis, we describe a simple yet practical parallel method to realize novel multi-furcated 3D micro/nanostructures by using the assembly of charged aerosols via spatial differentiation of electric field at atmospheric condition. A combination of generating charged aerosols by spark discharge and manipulating 3D electric field together with ion-induced electrostatic lenses lead to the formation of exotic 3D multi-furcated structures consisting of nanoparticles. By changing the arrangement of dielectric pre-patterns on the silicone substrate, bi-, tri-, tetra- or penta-furcated 3D nanoparticle structures and even interconnections between neighboring structures are precisely controlled. Based on these 3D multi-furcated micro/nanostructures, we propose a novel 3D gas sensor consisting of copper oxide nanoparticles, which exhibits excellent gas sensitivity significantly superior to that of two dimensional film type by more than 200 %. Also, we fabricate the sensor array with CuO and SnO2 nanoparticle bridge structures to demonstrate the selective detecting of NO2 and H2.