Microfluidic static droplet arrays with tuneable gradients in material composition†
Abstract
We describe a one-step passive strategy to create concentration gradients in static droplet arrays. The technique exploits controlled exchange of materials between moving plugs and stationary drops. The concentration of soluble reagents can be varied from drop-to-drop in the presence of other soluble reagents or insoluble materials (e.g.cells) at well-defined time points.