Efficient Charging of Aerosol Nanoparticles by Corona-needle Charger with Improved Design for Printing of Metallic Microstructures

Abstract

Aerosol particle charging is widely used in various technical applications. A model of a needle-plate type charger for efficient charging of aerosol nanoparticles in a corona plasma discharge has been developed and investigated. The main difference from similar devices in the modernization of the grounded plate hole's geometry and the number of corona needles exist. This has resulted in a substantial increase in the charger's efficiency by over 25%. The effects of two types of discharge plates, one with cylindrical and the other with conical inner holes, on the extrinsic charging efficiency of aerosol particles were experimentally investigated. Metallic nanoparticles of Ag with sizes ranging from 20 to 160 nm and a number concentration of 10 6 to 10 8 cm -3 were utilized as the test aerosol. This system shows that the maximum efficiency of particle charging is attained by using a plate with a conical hole, which reduces electrostatic losses from 37±3% to 20±2%. Furthermore, an additional effect of increasing the particle charging efficiency was also observed by using a multi-pointed needle, which resulted in lower electrostatic losses compared to a single needle. Experimental evidence confirms that utilizing a conical hole in the plate and a multi-pointed needle has increased the particle charging efficiency from 47±3% to 59±4%, as opposed to the standard design featuring a cylindrical hole and a single-pointed needle. In this paper, an increase in the efficiency of charging particles in a charger with a multi-pointed needle compared to a single-pointed one is shown for the first time.