Active Pneumatic Control of Automated Picoinjection for Regulating Droplet Contents Inside Microfluidic Chips

A method for picoinjection in a microfluidic chip via pneumatic control.The microfluidic chip consists of a fluidic channel layer, an elastic film layer, and a pneumatic control layer.Numerical simulation results show that the venturi structure injects into the droplet with less pressure. When the voltage was increased from 0.1V to 0.25V, the diameter of the injected droplet increased, and when the voltage signal continued to increase, the droplet diameter was unstable.The injected dose is affected by the injection phase velocity, the continuous phase velocity and the dispersed phase velocity.The preparation of calcium alginate microcapsules was achieved by this approach.