Abstract |
A pressure-driven microfluidic device (100, 120, 200, 300, 400, 550, 601) for separating chemical or biological species from a sample includes on-column injection, namely, a separation channel (114, 142, 281, 310, 320, 330, 340, 350, 360, 370, 380, 420, 440, 460, 480, 561) containing stationary phase material (115, 138, 291, 319, 329, 339, 349, 359, 369, 379, 389, 429, 449, 469, 489, 571) and a sample input (110, 135A, 236A-236H, 314, 324, 334, 344, 354, 360A, 374, 384, 427A, 427B, 447, 467A, 467B, 487) disposed between a first end (114A, 142A, 281A, 310A, 320A, 330A, 340A, 350A, 360A, 370A, 380A, 420A, 440A, 460A, 480A, 561A) and a second end (114B, 142B, 281B, 310B, 320B, 330B, 340B, 350B, 360B, 370B, 380B, 420B, 440B, 460B, 480B, 561B) of the separation channel or column. One or many separation channels may be provided in a single microfluidic device, which may be fabricated with sandwiched stencil layers (102, 103, 122, 125, 202-208, 302, 305, 402, 405, 408) using various materials including polymers. Sealing means associated with a sample input, such as a mechanical seal (520, 530, 606) adapted to selectively seal the sample input, are provide. Various sample injector configurations are provided. A separation system including a microfluidic device having on-column injection further includes a pressure source (603) and a detector (607). |