Abstract: A threadless interface for a fluidic system includes a microfluidic device having an outer surface and an internal near-surface channel having a first width and disposed at a first depth relative to the outer surface, with the first width being less than about two times the first depth. A fluidic seal engages the outer surface and exerts an elevated contact pressure against at least a portion of the outer surface without substantially occluding the channel. A preferred seal includes a raised boss. A fault tolerant flow path design can accommodate misalignment between adjacent device layers without detrimentally affecting fluid flow capability. The interface may be used in a microfluidic system for performing parallel analyses such as high performance liquid chromatography.

Abstract: Fluidic systems, including microfluidic systems, are used to manipulate light by light-fluid interaction so as to affect reflection, refraction, absorption, optical filtering, or scattering of the beam. One or more fluids may be provided to a channel or chamber and exposed to an incident beam, and the proportion of at least one of a plurality of fluids may be varied. Light may interact with a discrete fluid plug subject to movement within a channel. One or more flexible members may be employed, such as to provide a variable lens. Fluidic optical devices may be used in applications including optical switching, optical filtering, or optical processing. Multiplexed fluidic optical systems are further provided.

Abstract: Gasketless interfaces between microfluidic devices and related systems or instruments are provided. A microfluidic device includes a plastically deformable outer layer defining at least one port. An external mating surface having a protruding feature is aligned with the fluidic port defined in the microfluidic device. An actuator depresses at least a portion of the protruding feature into the outer layer adjacent to the fluidic port to cause the protruding feature to plastically deform the outer layer so as to form a reverse impression of the feature. Preferred materials are non-degrading in the presence of and non-absorptive of samples and solvents typically utilized in performing liquid chromatography. Systems for performing chromatography utilizing gasketless interconnects and at least one method for fabricating a multi-feature seal plate are provided.

Abstract: A pressure-driven microfluidic device for separating chemical or biological species from a sample provides an on-board stationary phase packing manifold or distribution network for simultaneously packing multiple separation channels. The packing manifold or distribution may include both a stationary phase inlet port and a vent port, and the vent port may include an associated porous material or frit. Methods for operating pressure-driven microfluidic separation devices include the steps of venting the packing manifold to an environment having a lower pressure than that present in the separation columns to allow any retained sample portions to migrate away from the separation channels, thereby minimizing or eliminating cross-talk and sample contamination.