Concepedia

Ultrasensitive Mass Sensing with a Nanotube Electromechanical Resonator

B. Lassagne, David García-Sánchez, Albert Aguasca, Adrian Bachtold

Nano Letters · 2008 · 400 citations · 26 references

TL;DR

Shrinking mechanical resonators to sub‑micrometer dimensions (~100 nm) has greatly enhanced sensing capabilities. The study aims to push size limits further by employing a 1 nm diameter carbon nanotube as a mechanical resonator for mass sensing. The authors fabricate and operate this 1 nm diameter carbon nanotube resonator to detect mass changes. The device achieves an exceptional mass responsivity of 11 Hz / yg and a room‑temperature mass resolution of 25 zg, improving to 1.4 zg at 5 K.

Abstract

Shrinking mechanical resonators to submicrometer dimensions (approximately 100 nm) has tremendously improved capabilities in sensing applications. In this Letter, we go further in size reduction using a 1 nm diameter carbon nanotube as a mechanical resonator for mass sensing. The performances, which are tested by measuring the mass of evaporated chromium atoms, are exceptional. The mass responsivity is measured to be 11 Hz x yg(-1) and the mass resolution is 25 zg at room temperature (1 yg = 10(-24) g and 1 zg = 10(-21) g). By cooling the nanotube down to 5 K in a cryostat, the signal for the detection of mechanical vibrations is improved and corresponds to a resolution of 1.4 zg.