A Miniature Aerosol Sensor for Detecting Polydisperse Airborne Ultrafine Particles.

Chao Zhang,Wenming Yang,Peng Jiang,Dingqu Wang,Rong Zhu

doi:10.3390/s17040929

Abstract

Counting and sizing of polydisperse airborne nanoparticles have attracted most attentions owing to increasing widespread presence of airborne engineered nanoparticles or ultrafine particles. Here we report a miniature aerosol sensor to detect particle size distribution of polydisperse ultrafine particles based on ion diffusion charging and electrical detection. The aerosol sensor comprises a couple of planar electrodes printed on two circuit boards assembled in parallel, where charging, precipitation and measurement sections are integrated into one chip, which can detect aerosol particle size in of 30–500 nm, number concentration in range of 5 × 102–5 × 107 /cm3. The average relative errors of the measured aerosol number concentration and the particle size are estimated to be 12.2% and 13.5% respectively. A novel measurement scheme is proposed to actualize a real-time detection of polydisperse particles by successively modulating the measurement voltage and deducing the particle size distribution through a smart data fusion algorithm. The effectiveness of the aerosol sensor is experimentally demonstrated via measurements of polystyrene latex (PSL) aerosol and nucleic acid aerosol, as well as sodium chloride aerosol particles.

Highlights

Industrial environment, indoor and atmospheric contains airborne ultrafine particles and engineered nanoparticles [1,2], which pose a recognized health threat to hundreds of millions of people throughout the world [3,4,5]
The researches indicate that the particle size smaller than about 10 μm which are accounted as PM10 can enter nasal cavity, and the particle size smaller than about 2.5 μm which are accounted as PM2.5 can enter lungs [9,10], which become pronounced in susceptible groups of the population such as infants, elderly and patients with chronic obstructive pulmonary disease (COPD)
We previously reported a micro aerosol sensor based on diffusion charging for detecting ultrafine particles in number concentration from 3 × 102 to 2.5 × 104 /cm3 and particle size from 50 to 253 nm [28]

Summary

Introduction

Industrial environment, indoor and atmospheric contains airborne ultrafine particles and engineered nanoparticles [1,2], which pose a recognized health threat to hundreds of millions of people throughout the world [3,4,5]. It is essential to have quantitative information on particle exposure levels for epidemiological and toxicological studies [6], searching for the relationship between human pathology and aerosol particle size distribution. A short review of human respiratory system illustrated a complexity relationship between human respiratory organs and airborne particles inhalation [7,8]. When the particle size further decreases to ultrafine particles or nanoparticles, the particles can enter alveolar area and even human blood circulation system [11,12], which arouse a higher risk to human health.

Methods

Results

Conclusion