# Accurate mass measurement of a levitated nanomechanical resonator for precision force sensing

## TL;DR

This paper introduces a new method for precisely measuring the mass of a levitated nanoparticle, significantly reducing uncertainties and enhancing the accuracy of nanomechanical sensors for force and mass detection.

## Contribution

A novel measurement protocol using electrical driving to determine nanoparticle mass with less than 1% statistical and 2% systematic error.

## Key findings

- Mass measurement uncertainty reduced to below 1%.
- Method enables more reliable sensing in levitodynamics.
- Improves accuracy for force and mass sensing applications.

## Abstract

Nanomechanical resonators are widely operated as force and mass sensors with sensitivities in the zepto-Newton and yocto-gram regime, respectively. Their accuracy, however, is usually undermined by high uncertainties in the effective mass of the system, whose estimation is a non-trivial task. This critical issue can be addressed in levitodynamics, where the nanoresonator typically consists of a single silica nanoparticle of well-defined mass. Yet, current methods assess the mass of the levitated nanoparticles with uncertainties up to a few tens of percent, therefore preventing to achieve unprecedented sensing performances. Here, we present a novel measurement protocol that uses the electrical field from a surrounding plate capacitor to directly drive a charged optically levitated particle in moderate vacuum. The developed technique estimates the mass within a statistical error below 1% and a systematic error of 2%, and paves the way toward more reliable sensing and metrology applications of levitodynamics systems.