Controlled focusing of silver nanoparticles beam to form the microstructures on substrates

The aerodynamic focusing in the coaxial nozzle and deposition on substrates of silver nanoparticles beams at the high subsonic speeds has been studied. The multi-spark discharge generator was used as a source of silver nanoparticles. We established that controlling the high-speed sheath flow allows to provide the minimization of the aerosol beam diameter for 4 times and printing of silver lines with width up to 60 μm using a nozzle 100 μm in outlet diameter. It was realized due to usage of high-speed beams of silver nanoparticle agglomerates, with the size of 25-110 nm, consisting of the primary particles with diameter of 5-10 nm. The agglomeration effect of aerosol nanoparticles plays a positive role providing particle deposition onto a substrate and substantially reducing diffusion broadening of an aerosol beam.