An universal microfluidic dual-mode shear droplet preparation structure

Abstract In this paper, three shear modes of a dual-mode passive shear structure are investigated. Three shear modes of the structure are verified by simulations and experiments. This structure can produce droplets of a wide range of viscosities, with the maximum viscosity exceeding 0.1 Pa·s, and for low-viscosity systems with a shear viscosity less than 0.1 Pa·s, a wider range of droplet sizes can be achieved. The coefficient of variation value of droplet sizes is all less than 8%, and the flow rate ratio of the dispersed phase to the continuous phase can be greater than 1, significantly enhancing the effectiveness of the shearing process. Considering the production flow velocity of the dispersed phase and the viscosity of the droplets, an index number <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msup> <mml:mrow> <mml:msub> <mml:mi>R</mml:mi> <mml:mi>A</mml:mi> </mml:msub> </mml:mrow> <mml:mo>∗</mml:mo> </mml:msup> </mml:mrow> </mml:math> for evaluating the efficient shearing structure by passive shearing structures is proposed. Compared with the single passive shear structure, the dual-mode shear structure has a significantly universality.