Multi-walled carbon nanotube films for the measurement of the alcoholic concentration

TL;DR

This paper demonstrates that multi-walled carbon nanotube films can serve as low-cost, reusable sensors for measuring alcohol concentration in liquids by monitoring changes in electrical resistance.

Contribution

It introduces a novel application of MWCNT films as a simple, effective sensor for alcohol detection in liquids, with linear response and reusability.

Findings

Resistance increases linearly with alcohol concentration.

Sensor response is fast and reversible.

Applicable to various beverages for quality control.

Abstract

We show that a multi-walled carbon nanotube film can be used as the sensing element of a low-cost sensor for the alcoholic concentration in liquid solutions. To this purpose, we investigate the electrical resistance of the film as a function of the isopropanol concentration in a water solution. The analysis reveals a growing resistance with increasing isopropanol concentration and a fast response. The sensing element is re-usable as the initial resistance value is restored once the solution has evaporated. The electrical resistance increases linearly when the multi-walled carbon nanotube film is exposed to common beverages with increasing alcoholic content. This work paves the way for the development of low-cost, miniaturized MWCNT-based sensors for quality monitoring and control of alcoholic beverages and general liquid solutions.