Abstract: An example system includes a passive dampener device having a chamber to hold a fluid. The passive dampener device is fluidically coupleable to a pump and a microfluidic device. The chamber has an air headspace to dampen pressure waves created by the pump in a sample fluid flow through the microfluidic device.

Abstract: Described are devices, methods, and kits for controlled incremental filtration (CIF), as well as methods of designing CIF devices. For example, a method for CIF may modulate a concentration of particles of a desired size in a fluid. The fluid including the particles may be flowed along a flow path through a central channel to contact a plurality of gaps that fluidically couple the central channel to at least one adjacent side channel network. Flow resistance may be decreased along at least a portion of the flow path effective to modulate the concentration of particles. The method may include selecting the plurality of gaps to be larger than the particles. The method may include causing a consistent flow fraction fgap in the central channel to traverse each gap in the plurality of gaps and flow through the at least one side channel network along the flow path.

Abstract: Described are systems, methods, and kits for compression sedimentation and whole blood separation. For example, a compression sedimentation system may include a compression stage configured to accept a flexible reservoir configured to contain a liquid mixture. The compression stage may include a base substrate and a compression substrate configured to apply a force to the flexible reservoir effective to create a pressure in the liquid mixture. An apparatus for whole blood separation may include a sedimentation system that separates whole blood into a supernatant including platelet rich plasma and a subnatant including red blood cells. At least one platelet-concentrating device may be included to receive the supernatant including the PRP and to separate a platelet concentrate and a platelet poor plasma from the supernatant.