Abstract
Complex flow patterns play a critical role in arterial thrombosis, yet the specific contribution of vorticity-the rotational component of fluid flow-remains poorly understood. An innovative microfluidic platform with systematically varied expansion angles (β = 30°-150°) in a double stenosis design is developed to isolate vorticity's effects under controlled conditions. The high expansion-ratio device with sharp-angled geometries successfully generates distinct vortical flow patterns, confirmed through computational and experimental flow visualizations. Real-time confocal microscopy revealed a strong positive correlation (r = 0.6698) between vorticity magnitude and thrombus size, with high-vorticity conditions producing thrombi up to four times larger than low-vorticity settings. Mechanistic investigations demonstrated enhanced von Willebrand Factor (vWF) accumulation and platelet integrin activation in vortical environments. Platelets in high-vorticity regions exhibited integrin αIIbβ3 intermediate activation states with significantly enhanced calcium signaling, suggesting vorticity amplifies platelet mechanosensing pathways. Inhibition of the interaction between vWF and platelet glycoprotein Ibα (GPIbα) receptor abolished biomechanical platelet aggregation in vortical regions. These findings provide valuable insights into platelet thrombosis in complex flow environments with significant implications for optimizing medical devices to minimize thrombotic complications associated with vortex formation.