Use of metal mesh sensors with periodic microstructures to sense and separate aerosol particles in Kenya

This study introduces a new optical metal mesh (MM) sensor for detection of aerosol particles. The base material of the sensor corresponds to a thin metal membrane with unique optical properties and a micromesh structure. A small air pump pulls air through the MM membrane, permitting capture of aerosol particles on the micromesh surface and subsequent detection of the particles via infrared (IR) techniques. Here, MM membranes with different square apertures (side length: 4.0, 1.8, or 1.1 μm) were combined to form two-membrane stacked MM sensors. The sensors were used to collect particulate matter 2.5 (PM2.5; average diameter: ≤ 2.5 μm) as an indication of environmental pollution in the suburbs of Nairobi, Kenya. The elemental composition of each particle within captured PM2.5 was determined via wavelength-dispersive X-ray spectrometry. The results suggest that stacked MM sensors can successfully provide information about aerosol particle pollutants in the local environment.