Trapping and collection of uniform size droplets using a well array inside a microchannel

This paper presents a simple and fast method for droplet trapping and collection. This method is size-dependent, therefore droplets having various sizes caused by unstable inlet flows can be eliminated. There is no need for any additional controls for selective trapping of droplets, and all trapped droplets can be simply collected at the outlet. We had verified the capability of aqueous droplet trapping and collection using hexadecane as the continuous phase. Due to its simplicity and high efficiency for selective trapping and collection, this method can become one of the key essentials in droplet-based microfluidic assays such as single cell analysis or nanoparticle synthesis.