A method and apparatus involving the configuration of an open capillary channel for size-based separation of analytes is described. The open capillary channel contains numerous turns of defined angles separated by intervening linear or curvilinear segments of capillary tubing. The configuration of the channel allows analyte differentiation based on diffusion coefficients and thus separates analytes by size.

Methods, devices, and systems for performing nebulization of a sample from a fluid channel of a microfluidic device are described. The systems or devices disclosed herein may comprise microfluidic devices that comprise a gas channel used for nebulization of the sample at a fluid outlet of the microfluidic device. In some instances, the disclosed devices may be designed to perform isoelectric focusing followed by further characterization of the separated analytes using electrospray ionization coupled with nebulization to introduce the samples into a mass spectrometer. The disclosed methods, devices, and systems provide for fast, accurate separation and characterization of protein analyte mixtures or other biological molecules by isoelectric point.

Aspects of enhanced nanoscale gas chromatography are described. In one embodiment, a nano-scale gas chromatography (GC) module includes a light source, a light detector, and a sensor module having vertically-integrated photonic crystal slab (PCS) Fano resonance filter and GC channel layers. The PCS Fano resonance filter layer includes a hole lattice region, and the GC channel layer comprises a gas channel for separation of analytes in a gas mixture. The gas channel includes a coiled section and an extended length section, where the extended length section extends through a region in the GC channel layer that is stacked in proximity with the hole lattice region. The hole lattice region in the PCS Fano resonance filter layer provides local field enhancement of light generated by the light source for increased light-matter interaction with the analytes in the gas channel.

A chemical reactor is implemented on a substrate and has an inlet for receiving a fluid and/or a gas; a filter element for reducing or preventing that materials cause a blockage in the fluid supplied and/or the gas supplied in a part of the chemical reactor located further away; and a part located further away for transporting and/or processing the fluid and/or the gas. The part located further away has a depth dlow smaller than the depth dhigh of the inlet. The filter element has a first duct part and a second duct part; the first duct part is positioned closer up against the inlet than the second duct part, the first duct part is deeper than the second duct part, the first duct part has a diverging width and is free from pillar structures, and the second duct part is filled with filter pillars.

An apparatus for chemical separations includes a first substantially rigid microfluidic substrate defining a first fluidic port; a second substantially rigid microfluidic substrate defining a second fluidic port; and a coupler disposed between the first and second substrates, the coupler defining a fluidic path in fluidic alignment with the ports of the first and second substrates. The coupler includes a material that is deformable relative to a material of the first substrate and a material of the second substrate. The substrates are clamped together to compress the coupler between the substrates and form a fluid-tight seal.

A microfluidic check valve includes an inlet bore, an internal chamber, an outlet bore, and a disk freely movable in the chamber between an open position and a closed position. At the open position, the disk permits fluid to flow from the inlet bore, through the chamber, and to the outlet bore. At the closed position, the disk prevents fluid from flowing in the reverse direction from the chamber into the inlet bore. The check valve may be positioned in-line with a fluid conduit, and/or incorporated with various fluidic devices such as, for example, capillary tubes, fittings, and chromatography columns. The check valve is capable of withstanding high fluid pressures, while featuring a small swept volume, such as a nano-scale volume. The check valve may be utilized, for example, to prevent fluid back flow and isolate pressure pulses in fluid flow systems.

A microfluidic interconnect system and method for assembly thereof is described. The microfluidic interconnect has a port and a seal, with the port having a reverse taper. The port has a first port end, a second port end, and an inner port surface with a tapered portion. Each port end has an opening with a diameter, and in certain embodiments, the diameter of the first port end is smaller than the diameter of the second port end. The seal has a first end and a second end, and each seal end has a rim and an opening with an inner diameter and an outer diameter. The seal also has an inner surface and an outer surface, where in certain embodiments, each surface has a tapered portion. In certain embodiments, the inner diameter of the first seal end is equal to or larger than the inner diameter of the second seal end, the outer diameter of the first seal end is equal to or smaller than the outer diameter of the second seal end, and the outer diameter of the second seal end is larger than the outer diameter of each port end. In certain embodiments, a tube is slidably coupled to the inner surface of the seal, and the tube has an outer diameter that is equal to or larger than the inner diameter of the second seal end.

A chemical reactor is implemented on a substrate. The chemical reactor has multiple ducts for transporting a fluid and/or gas during use of the chemical reactor, in which the ducts optionally include pillar structures and at least one connection duct connected between two of the multiple ducts for transporting the fluid and/or gas from one duct to another. In the connection duct, a series of individual pillar structures are positioned behind each other in the longitudinal direction of the connection duct.

A gas chromatography system can include a circulatory loop, a gas inlet positioned along the circulatory loop, a gas outlet positioned along the circulatory loop, a micro column positioned in line with the circulatory loop, and an in-line population sensor positioned in line with the circulatory loop. The in-line population sensor can be configured to detect changes in gas population. The gas inlet and gas outlet can be associated with a gas inlet valve and gas outlet valve, and configured to admit or withdraw gas from the circulatory loop, respectively. A gas sample can be circulated through the circulatory loop for at least one cycle, and a component of the gas sample can be detected using the in-line population sensor.

The present invention provides a microfluidic purification chip for capturing a biomarker from a physiological solution. The present invention also provides a method of capturing and releasing a biomarker, wherein the biomarker is originally in a physiological solution. The present invention further provides a method of pre-purifying and measuring the concentration of a biomarker in a physiological solution.