US 11,786,899 B2
Trap arrays for robust microfluidic sample digitization
Don L. DeVoe, Bethesda, MD (US); and Alex Sposito, Arlington, VA (US)
Assigned to University of Maryland, College Park, College Park, MD (US)
Filed by University of Maryland, College Park, College Park, MD (US)
Filed on Feb. 2, 2018, as Appl. No. 15/887,676.
Claims priority of provisional application 62/514,501, filed on Jun. 2, 2017.
Claims priority of provisional application 62/453,763, filed on Feb. 2, 2017.
Prior Publication US 2018/0214873 A1, Aug. 2, 2018
Int. Cl. C12Q 1/686 (2018.01); B01L 3/00 (2006.01); B01L 7/00 (2006.01)
CPC B01L 3/502753 (2013.01) [B01L 3/50273 (2013.01); B01L 7/52 (2013.01); C12Q 1/686 (2013.01); B01L 2200/027 (2013.01); B01L 2200/0605 (2013.01); B01L 2200/12 (2013.01); B01L 2300/0645 (2013.01); B01L 2300/0816 (2013.01); B01L 2300/0819 (2013.01); B01L 2300/0858 (2013.01); B01L 2300/0864 (2013.01); B01L 2300/0893 (2013.01); B01L 2400/0406 (2013.01); B01L 2400/0688 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A method comprising:
providing a substrate having a first microfluidic channel provided therein, the first microfluidic channel being in fluid communication with an inlet port and an outlet port and a plurality of sample traps branching directly off the first microfluidic channel, wherein a second microfluidic channel is in fluid communication with an immiscible fluid inlet port and a plurality of immiscible fluid outlet ports, and wherein between the immiscible fluid inlet port and the immiscible fluid outlet ports the second microfluidic channel is in fluid communication with each of the plurality of sample traps which are arranged in rows on both sides of the second microfluidic channel, such that at least a portion of the first and second microfluidic channels are parallel to each other with the plurality of sample traps disposed there-between,
wherein the first microfluidic channel connects the inlet port to a capillary pump with the sample traps in between, wherein a sealing layer is bonded to the substrate;
introducing a sample into the first microfluidic channel through the inlet port, wherein the sample is self-filled into the sample traps;
removing an excess sample from the first microfluidic channel by the capillary pump;
introducing an immiscible fluid into the second microfluidic channel through the immiscible fluid inlet port;
filling the second microfluidic channel with an immiscible fluid, wherein the immiscible fluid isolates the sample traps; and
wherein each of the plurality of traps has geometrical parameters selected to optimize self-filling of the sample traps with the sample via pinning, wherein an advancing fluid front of the sample will be pinned to one or more surfaces of the channel, such that the advancing fluid front will expand beyond a critical angle causing the sample to enter a sample trap.