Investigating the swelling behavior of superabsorbent polymer microparticles (SAP-MPs) at a single-particle level using traditional methods is constrained by low resolution and insufficient real-time data, especially for particles smaller than 300 µm. To address these challenges, a novel microfluidic device capable is developed of real-time, high-precision single-particle analysis. This platform hydrodynamically traps individual SAP-MPs, enabling continuous monitoring of their swelling dynamics under controlled conditions. SAP-MPs with varying sizes (90-270 µm), crosslinker concentrations (0.25%<
Cr<
2%), neutralization degrees (50%<
ND<
100%), and acrylic acid concentrations (10%<
AA<
90%) are synthesized via inverse suspension polymerization and systematically studied using the response surface method (RSM). Kinetic modeling revealed the dominance of the pseudo-first-order (PFO) model over the pseudo-second-order (PSO) model in describing diffusion-driven swelling dynamics. The PFO model demonstrated superior predictive accuracy (R