The motion trajectories of aerosol particles based on TOPS and the experimental verification thereof

To identify the compositional characteristics of particulate matter and separate particles of varying sizes, this study developed a T-type optical particle separation chip (TOPS) based on optofluidic technology, which aims to provide scientific guidance for addressing atmospheric particulate pollution. The study investigated the effect of optical radiation forces on particles of different sizes and introduced a dimensionless parameter S to characterize particle motion within the TOPS system. Particles in the channel were deflected by laser radiation forces acting perpendicular to the fluid flow, with varying deflection distances depending on particle size, enabling the separation of particles by size. Additionally, an optofluidic experimental system was designed and validated. The results showed relative errors of 8.76%, 4.03%, and 8.83% in the deflection distances of 2 μm, 5 μm, and 15 μm particles, respectively, demonstrating the effectiveness of the dimensionless parameter and the preliminary feasibility of the separation system.