Ultrasensitive nanoelectromechanical mass detection

TL;DR

This paper demonstrates that nanoelectromechanical systems can achieve extremely sensitive mass detection, capable of sensing individual molecules, with potential for further optimization to reach fundamental noise limits.

Contribution

It introduces a NEMS-based mass sensor with unprecedented sensitivity and analyzes the fundamental noise limits affecting its performance.

Findings

Achieved mass sensitivity of 2.53x10^-18 g.

Measured resonance frequency shifts due to adsorbed atoms.

Identified fundamental phase noise as the ultimate sensitivity limit.

Abstract

We describe the application of nanoelectromechanical systems (NEMS) to ultrasensitive mass detection. In these experiments, a modulated flux of atoms was adsorbed upon the surface of a 32.8 MHz NEMS resonator within an ultrahigh vacuum environment. The mass-induced resonance frequency shifts by these adsorbates were then measured to ascertain a mass sensitivity of 2.53x10^-18 g. In these initial measurements, this sensitivity is limited by the noise in the NEMS displacement transducer; the ultimate, limits of the technique are set by fundamental phase noise processes. Our results and analysis indicate that mass sensing of individual molecules will be realizable with optimized NEMS devices.