Pressure-driven generation of complex microfluidic droplet networks

Droplet interface bilayers (DIBs) mimic the cell membrane and provide a model membrane platform for studying basic biophysical processes. This paper demonstrates a pressure-driven microfluidic system for the rapid and automated generation of alternating DIB networks, each comprised of four aqueous nanoliter droplets. The microfluidic device features five inlets, one for the continuous oil phase and four independent aqueous channels for T-junction droplet generation. Droplet production rates are controlled by adjusting the applied pressure of each inlet; therefore, controlling the pattern of droplets produced in the main channel and further stored in a downstream hydrodynamic trapping array. Each trap is designed to capture and hold in place one row of four droplets, forming three interfacial lipid bilayers per network. The potential for greater combinations of droplets in a network enables an increased complexity necessary for performing parallel multiplexed biological assays. We further examined flow behavior in response to changes in resistance of the microfluidic device when using a pressure driven source. This microfluidic system provides a high-throughput method for generating DIB networks of complex droplet patterning.