Particle deposition has a wide application in many fields including bioengineering, chemical engineering and also greatly impacts our daily life. For example, because people spend more time indoors than outdoors nowadays, their health is influenced by indoor air quality. Particles smaller than 10 μm (PM10) are easily inhaled, leading to serious lung diseases. Many aerosol removal systems are not efficient for submicron particles (0.1-1 μm). It was reported that small-scale obstructions can enhance particle deposition, therefore helping to provide better indoor air quality. The objective of this work is to investigate the effect of particle deposition on microstructured surfaces in a turbulent chamber.

In this study, the microstructures on the studied surfaces are realized by microfabri...[ Read more ]

Particle deposition has a wide application in many fields including bioengineering, chemical engineering and also greatly impacts our daily life. For example, because people spend more time indoors than outdoors nowadays, their health is influenced by indoor air quality. Particles smaller than 10 μm (PM10) are easily inhaled, leading to serious lung diseases. Many aerosol removal systems are not efficient for submicron particles (0.1-1 μm). It was reported that small-scale obstructions can enhance particle deposition, therefore helping to provide better indoor air quality. The objective of this work is to investigate the effect of particle deposition on microstructured surfaces in a turbulent chamber.

In this study, the microstructures on the studied surfaces are realized by microfabricated rib patterns. The relationship between the particle deposition effect and the geometrical parameters of the ribs was studied experimentally. Four different rib shapes, rectangular, triangular, and convex semi-circular, as well as concave semi-circular were studied. For each shape, different ratios of rib pitch to rib height were investigated. Particles including submicron and micron size were tested. The results show that both the shape and aspect ratio of the surface microstructure have obvious effects on particle deposition for different particle sizes. For submicron particles (0.1 to 1 μm), microstructures show a significant enhancement effect on particle deposition. The performance of triangular ribs is best, while the effect gradually vanishes as the rib pitch-to-height ratio increases. For particles in the range of 1 to 10 μm, microstructures show a slightly adverse effect on particle deposition. On submicron particles, the ‘selectivity’ effect of microstructures could be a reference for considering efficiency enhancement of aerosol removal systems. Here, a general theoretical explanation is given to explain the findings including both sub and above micron sized particle deposition.