Manipulation and analysis of an optofluidic multiphase microlens

An optofluidic microlens was investigated in this study by using a gas–liquid interface, and the underlying physics of the microlens formation was exploited by considering fluid parameters that control the shape of the microlens. A microfluidic device was designed and fabricated to secure a stable multiphasic interface in the channel. A theoretical model based on the coupled Stokes–Cahn–Hilliard equations was proposed to understand the characteristics of the lens formation in the device. The results show that nonlinear flow behavior near the gas–liquid interface affects the interface shape due to the effect of surface tension, and the extent of the lens symmetry is inversely proportional to the product of the capillary number (Ca) and Reynolds number (Re).