Abstract: The present disclosure generally relates to microfluidics, and to systems and methods for controlling the flow of fluids. Certain aspects are generally directed to microfluidic channels that are parallel to each other, e.g., within a microfluidic interconnected region of a microfluidic device. In some embodiments, a fluid in a first microfluidic channel may be prevented from entering a second microfluidic channel due to a trench or other feature separating the channels. The trench may include features that at least partially prevent fluid from crossing. For example, the ends of the trench may be positioned such that fluids cannot access the ends, e.g., due to overhang regions between the trench and the microfluidic channels. This may keep the fluids pinned within the channels in some embodiments. Thus, for example, a fluid in a first microfluidic channel may be hardened to form a hydrogel, while the second microfluidic channel may remain free of the fluid and the hydrogel, due to the trench.

Abstract: The present disclosure generally relates to microfluidics, and to systems and methods for controlling the introduction of fluids. For example, certain aspects are generally directed to microfluidic devices having ports able to direct the end of a pipette tip into an end portion that is sized so as to allow fluid to flow from the pipette tip into an exit fluidly connected to a microfluidic channel. For example, the port may have a tapered portion that directs the pipette tip to the end portion. The end portion may be sized such that it is difficult for fluid to backflush around the pipette tip, and thus, the fluid is able to flow into microfluidic channels within the device, e.g., without resulting in excessive fluid remaining within the end portion. Other aspects are generally directed to methods of making or using such microfluidic devices, kits including such microfluidic devices, and the like.

Abstract: The present disclosure generally relates to microfluidic devices, which may contain hydrogels in certain embodiments. In some aspects, a hydrogel or other scaffold medium may be present within a first microfluidic channel, and cells that are present may be imaged. The cells may be kept alive by exposure to cell media, which may be supplied via a second microfluidic channel. The first and second microfluidic channels may meet at a common interconnect region, in which the hydrogel can be directly exposed to the cell media, and nutrients, dissolved gases, waste, etc., can pass from the media to the cells or vice versa, e.g., through the hydrogel. In addition, in some cases, a polymer may be present between the hydrogel and the microfluidic channel, e.g., to position the hydrogel relative to one or more walls of the microfluidic channel. Other embodiments are generally directed to methods of making or using such devices, kits using such devices, or the like.

Abstract: The present disclosure generally relates to microfluidics, and to spatially controlling fluidic flows. In some embodiments, a fluid in a first microfluidic channel may be prevented from entering a second microfluidic channel due to a trench or other feature separating the channels. Using a trench may avoid the use of pillars, columns, bumps, or other barriers to separate the channels. Thus, for example, a fluid in a first microfluidic channel may be hardened to form a hydrogel, while the second microfluidic channel may remain free of the fluid and the hydrogel. This may allow a barrierless interface between the hydrogel and fluid within the second channel to be formed. Other embodiments are generally directed to devices containing such structures, methods or kits using such structures, or the like.