Temperature-free mass tracking of a levitated nanoparticle

Abstract

Mass measurement is an essential analytical tool in the characterization of materials. Here we present a method for measuring the mass of an individual nanoparticle which has a fg-level mass. This method enables a temperature-independent mass measurement with the assistance of a sinusoidal electrostatic driving force. With this approach, we successfully track the change in properties of an optically levitated nanoparticle, such as mass, temperature, and electric charge, with air pressure. An abrupt change in the mass of silica nanoparticles is found to violate the Zhuravlev model. This method can be utilized to extend the mass analysis of materials, such as thermogravimetric analysis, to individual micro-or nano-particles.