A microfluidics system for isolating individual sperm from a semen sample, the system comprising: a first laminar flow channel extending between a first inlet and a first outlet; a second laminar flow channel extending between a second inlet and a second outlet; and a third laminar flow channel extending between the first and second laminar flow channels (1501, 1502) and having a restriction configured to prevent passage of a single sperm through the third laminar flow channel, wherein flow of a semen sample through the first laminar flow channel at a pressure higher than flow of a liquid medium through the second laminar flow channel results in a single sperm being trapped by the restriction in the third laminar flow channel, the system further comprising: a fourth laminar flow channel connected between the first laminar flow channel and a third outlet; a first valve in the first laminar flow channel between the first inlet and the third laminar flow channel; a second valve in the first laminar flow channel between the fourth laminar flow channel and the first outlet; and a third valve in the fourth laminar flow channel between the first laminar flow channel and the third outlet, wherein, upon closing the first and second valves (1509, 1512) and opening the third valve, a sperm trapped by the restriction in the third laminar flow channel travels to the third outlet for collection. a first laminar flow channel extending between a first inlet and a first outlet; a second laminar flow channel extending between a second inlet and a second outlet; and a third laminar flow channel extending between the first and second laminar flow channels (1501, 1502) and having a restriction configured to prevent passage of a single sperm through the third laminar flow channel, wherein flow of a semen sample through the first laminar flow channel at a pressure higher than flow of a liquid medium through the second laminar flow channel results in a single sperm being trapped by the restriction in the third laminar flow channel, the system further comprising: a fourth laminar flow channel connected between the first laminar flow channel and a third outlet; a first valve in the first laminar flow channel between the first inlet and the third laminar flow channel; a second valve in the first laminar flow channel between the fourth laminar flow channel and the first outlet; and a third valve in the fourth laminar flow channel between the first laminar flow channel and the third outlet, wherein, upon closing the first and second valves (1509, 1512) and opening the third valve, a sperm trapped by the restriction in the third laminar flow channel travels to the third outlet for collection. a fourth laminar flow channel connected between the first laminar flow channel and a third outlet; a first valve in the first laminar flow channel between the first inlet and the third laminar flow channel; a second valve in the first laminar flow channel between the fourth laminar flow channel and the first outlet; and a third valve in the fourth laminar flow channel between the first laminar flow channel and the third outlet, wherein, upon closing the first and second valves (1509, 1512) and opening the third valve, a sperm trapped by the restriction in the third laminar flow channel travels to the third outlet for collection.