Abstract: The present subject matter relates to devices and techniques for reducing the parabolic velocity profile. The disclosed device can include a coflow generator configured to receive a buffer solution and a mixture of at least two components to form a coflow pattern in a tubing, and a coflow separator configured to seperate the buffer solution from the reaction mixture. The coflow generator and the coflow separator can be coupled through the tubing. The tubing can be configured to receive the mixture and the buffer solution from the coflow generator and have the mixture bounded by the buffer solution without contacting a wall of the tubing.

Abstract: The present subject matter relates to devices and techniques for preparing a sample. The disclosed device can include a mixer, a reaction channel, and a micro sprayer. The mixer can be configured to mix at least two components and perform a splitting and recombination (SAR) mixing. The micro sprayer can be configured to generate a droplet of the sample. The mixer and the micro sprayer can be coupled through the reaction channel. The reaction channel can be a microcapillary tubing or a yin-yang reaction channel.