Disclosed herein is a cell culture device and its applications of creating gradient of chemicals or gradient of cells to mimic the in vivo physiological conditions of homeostasis.

Described are a gradient system and method, wherein at least two fluids are mixed in accordance with a noise level threshold. An inlet receives the fluids. A pump head body has a mixing chamber therein in communication with the inlet. The mixing chamber has a first delay volume configured to mix the fluids having a noise level. A pump head extension has a mixing chamber extension therein extending from the mixing chamber. The mixing chamber extension increases the volume of the mixing chamber by a second delay volume to a third delay volume. The fluids are mixed in the third delay volume at a compositional noise level that is less than the noise level.

Disclosed is a method and apparatus for manipulating fluids. The apparatus may include a microfluidic structure including inlet channels (1 and 2) and outlet channels (306, 307, 308, 309, 310, 311, 312, 313, and 314) oriented among bifurcated (5), trifurcated (6) and merging junctions (7 and 8). The apparatus splits and merges fluids flowing in the channels to produce successive dilutions of the fluids within the outlet channels. Multiple apparatus may be combined in serial, parallel, combined serial and parallel and/or stacked configurations. One or more apparatus may be used alone or to provide various devices or chambers with the diluted fluids.

A microfluidic element for thoroughly mixing a liquid with a reagent used for the analysis of the liquid for an analyte contained therein and a method thereof are disclosed. The microfluidic element has a substrate and a channel structure. The channel structure includes an elongate mixing channel and an output channel. The mixing channel has an inlet opening and an outlet opening, and is implemented to mix the reagent contained therein with the liquid flowing through the inlet opening into the mixing channel. The outlet opening of the mixing channel is in fluid communication to the output channel. The outlet opening is positioned closer to the middle of the length of the mixing channel than the inlet opening.

A blending system includes one or more tank platforms. The tank platforms are transportable via road, rail, or vessel. One or more bulk containers are located on the tank platforms. The bulk containers are capable of storing and handling concentrated fluids. A blending platform may be coupled to the tank platforms. The blending platform is transportable via road, rail, or vessel. A blending unit is located on the blending platform. The blending unit blends the concentrated fluids with one or more of the additive fluids and water to continuously produce desired fluids as needed. The desired fluids may be used in a well in a subsurface of the earth. The flow of concentrated fluids and water may be automatically controlled to provide the desired fluid with one or more properties that vary over time with a selected variation profile.

A mixing system has a parallel droplet dispenser capable of making droplets of a first working material in the range of 10 nanometers to 10 micrometers, a pump to deliver fluid for the droplets of the first working material and to produce a first emulsion, a compact mixer having low inter-voxel mixing to receive the emulsion and produce a homogenous material, and a dispensing system. A method of dispensing a graded material includes generating droplets of a first working material, the droplets having a size in the range of 10 nanometers to 10 micrometers, adding the droplets of the first working material into a fluid to create a first emulsion, wherein addition of the droplets of the first working material is controlled to create gradient in the emulsion, mixing the first emulsion to create a homogenous, graded mixture, and dispensing the homogenous, graded mixture onto a surface.