Systems, methods, and devices for forming an array of emulsions. An exemplary device comprises a frame and at least one or a plurality of separate microfluidic modules mounted to the frame and each configured to form an array of emulsions. In some embodiments, each module may be mounted by snap-fit attachment. The device also may include the same sealing member bonded to a top side of each module and hermetically sealing each of the modules. Another exemplary microfluidic device for forming an array of emulsions comprises a stack of layers bonded together. The stack may comprise a port layer forming a plurality of ports. Each port may have a top rim formed by a protrusion that encircles the central axis of the port. The rims may be coplanar with one another to facilitate bonding of a sealing member to each rim.