A microfluidic binary logic device using inertia-elastic particle focusing

Abstract

While a few attempts have been made on microfluidic logic devices, e.g., digital microfluidics and a fluid transistor, complete integration of digitalization into microfluidics is still a challenge. In this study, we investigate a microfluidic logic device that is built based on the particle dynamics in viscoelastic fluid. A logic gate system employing a Boolean function is implemented by utilizing multiple line particle focusing behavior in the microfluidic channel. The device is designed and fabricated to hydrodynamically control the logic operations of XOR, OR, AND, Buffer, and NOT under the fixed flow condition (e.g., flow rate, particle size, and fluid elasticity∼1.483). In addition, numerical simulation is carried out to understand the fundamental physics of the particle and fluid behavior in viscoelastic flow. Clear multiple particle focusing lines with high separation resolution (Rij∼6.19) were observed and the particle extraction at the outlets were analyzed by image-processing. This study is expected to open a new route to the incorporation of microfluidics with electronics by demonstrating logic gates based on microfluidics.