Abstract: A system for isolating and emulsifying particles or cells within droplets includes a microfluidic trapping device having an inlet and an outlet and one or more channels disposed between the inlet and the outlet, at least some of the one or more channels having a plurality of expansion regions serially arranged along the length thereof. A droplet generation device is fluidically coupled to the outlet of the microfluidic trapping device, the droplet generation device has a plurality of channels of a first height that terminate at an interface into a chamber having a second height that is greater than the first height, wherein the plurality of channels droplet generation device and the chamber contain an oil phase therein and wherein the interface is a step junction. In some embodiments, the droplet generation device is itself oriented at an angle with respect to horizontal to prevent droplet coalescence.

Abstract: A microfluidic device for trapping circulating tumor cells includes at least one microfluidic channel coupled to an inlet and an outlet, the at least one microfluidic channel having a height of less than 50 ?m and a width less than 30 ?m. A plurality of expansion regions are disposed along the length of the at least one microfluidic channel, each of the plurality of expansion regions is formed by an abrupt increase in the width of the at least one microfluidic channel, wherein the width of each expansion region is within the range of 526 ?m to 626 ?m and continues for a length within the range of 814 ?m to 914 ?m along a length of the expansion region, followed by an abrupt decrease in the width of the at least one microfluidic channel back to a width less than 30 ?m.

Abstract: A system for isolating and emulsifying particles or cells within droplets includes a microfluidic trapping device having an inlet and an outlet and one or more channels disposed between the inlet and the outlet, at least some of the one or more channels having a plurality of expansion regions serially arranged along the length thereof. A droplet generation device is fluidically coupled to the outlet of the microfluidic trapping device, the droplet generation device has a plurality of channels of a first height that terminate at an interface into a chamber having a second height that is greater than the first height, wherein the plurality of channels droplet generation device and the chamber contain an oil phase therein and wherein the interface is a step junction. In some embodiments, the droplet generation device is itself oriented at an angle with respect to horizontal to prevent droplet coalescence.