Abstract: A microfluidic valve operable to semi-permanently close a channel of a microfluidic device defined between a thermoplastic elastomer (TPE) film and a substrate operates employs a surface contact bond between the TPE and a wall of the channel. Thermomechanical release of the valve, tristate functionality, and repeated semi-permanent closure and release are demonstrated.

Abstract: A composition made of at least 60 wt. % of a thermoplastic elastomer resin and additives that are solid at least from 0-50° C., that has a Shore A hardness that is less than about 50 bears a patterned surface, the pattern comprising at least one microfluidic channel having a cross-sectional dimension smaller than 100 microns is a substrate for forming a microfluidic device. The chief advantages of such compositions are: its ability to bond in a sealing manner to smooth surfaces of many different compositions, its ease of manufacture and microstructure patterning, and its general impermeability to liquids.

Abstract: A microfluidic system, particularly suited as a cell culture system, is provided having a single monolithic biocompatible substrate with both a surface having an ordered array of nano-scale elements required for plasmonic response monitoring and a network of microchannels for precisely controlling cellular environment. The system has the additional advantages of low-volume consumption, rapid low-cost fabrication of molds with easily interchangeable microfluidic channel layouts, amenability to mass production, and in situ label-free real-time detection of cellular response, viability, behavior and biomolecular binding using plasmonic techniques. A ratio of greater than 0.2 between the cross-sectional dimension and the spacing distance of the nano-scale elements is useful for plasmonic response monitoring.

Abstract: A microfluidic system has a monolithic biocompatible substrate with both a surface having an ordered array of nano-scale elements for plasmonic response monitoring and a network of microchannels. Advantageously, low-volume consumption, rapid low-cost fabrication of molds with easily interchangeable microfluidic channel layouts, mass production, and in situ label-free real-time detection of cellular response, viability, behavior and biomolecular binding using plasmonic techniques can be provided. A ratio of greater than 0.2 of the cross-sectional dimension and the spacing between the nano-scale elements is useful for plasmonic response monitoring. Producing such a system involves a master mold with the nano-scale elements etched into a hard substrate, and the network provided in a soft membrane bonded to the hard substrate. A stamp may be created by setting a settable liquid polymer or metal placed in the master mold. Features of the intended device can be transferred to a polymeric substrate using the stamp.

Abstract: A technique for separating components of a microfluid, comprises a self-intersecting micro or nano-fluidic channel defining a cyclic path for circulating the fluid over a receiving surface of a fluid component separating member; and equipment for applying coordinated pressure to the channel at a plurality of pressure control areas along the cyclic path to circulate the fluid over the receiving surface, applying a pressure to encourage a desired transmission through the separating member, and a circulating pressure to remove surface obstructions on the separating member. The equipment preferably defines a peristaltic pump. Turbulent microfluidic flow appears to be produced.

Abstract: A composition made of at least 60 wt. % of a thermoplastic elastomer resin and additives that are solid at least from 0-50° C., that has a Shore A hardness that is less than about 50 bears a patterned surface, the pattern comprising at least one microfluidic channel having a cross-sectional dimension smaller than 100 microns is a substrate for forming a microfluidic device. The chief advantages of such compositions are: its ability to bond in a sealing manner to smooth surfaces of many different compositions, its ease of manufacture and microstructure patterning, and its general impermeability to liquids.

Abstract: A centrifugal microfluidic device having a microfluidic mixing element with a microfluidic mixing chamber in which at least two flows emerging from channels into the chamber at separate places are redirected to land at substantially the same place on a mixing surface provides efficient mixing of two or more fluids in the chamber.

Abstract: In a centrifugal microfluidic device for conducting capture assays, a microfluidic platform rotates in a plane of rotation and has at least one capture surface for immobilizing a target particle of interest in the device. The capture surface oriented so that it is not parallel to the plane of rotation of the device and is positionally fixed in the device during operation of the device. The centrifugal force arising from rotation of the device forces the target particles against the capture surface. Capture efficiency is independent of the rate of flow of the fluid and independent of the rate of rotation of the microfluidic platform.

Abstract: A centrifugal microfluidic device is provided having a microfluidic circuit, a fluid reservoir for providing fluid in the microfluidic circuit, a hydrodynamic resistance element in fluid communication with the reservoir for controlling rate of flow of a fluid out of the reservoir, and a siphoned chamber in fluid communication with the hydrodynamic resistance element and the microfluidic circuit for receiving fluid from the hydrodynamic resistance element and for delaying and metering of the fluid into the microfluidic circuit. The microfluidic device is useful for performing a biological assay. Operation of the device is completely independent on the liquid-solid contact angle and wetting properties of the liquids on the solid material of the platform, and the device does not need a carefully controlled rotation protocol.

Abstract: A microfluidic system, particularly suited as a cell culture system, is provided having a single monolithic biocompatible substrate with both a surface having an ordered array of nano-scale elements required for plasmonic response monitoring and a network of microchannels for precisely controlling cellular environment. The system has the additional advantages of low-volume consumption, rapid low-cost fabrication of molds with easily interchangeable microfluidic channel layouts, amenability to mass production, and in situ label-free real-time detection of cellular response, viability, behavior and biomolecular binding using plasmonic techniques. A ratio of greater than 0.2 between the cross-sectional dimension and the spacing distance of the nano-scale elements is useful for plasmonic response monitoring.

Abstract: The invention provides a new process for patterning TPE membranes for use in the design and fabrication of 3D microfluidic devices. The process involves patterning a TPE material without permitting the highest features of the mold to come into contact with the counter-plate, whereby adhesion between the TPE and the mold or counter-plate during demolding results directly in removal of the excess layer from the TPE membrane to produce well formed micrometric-sized open-through holes in the TPE membrane. The process permits rapid, reliable and efficient patterning of densely packed and arbitrarily placed micrometric open-through holes and channels of high aspect-ratio and any shape or wall profile in thin TPE membranes.

Abstract: A microfluidic valve operable to semi-permanently close a channel of a microfluidic device defined between a thermoplastic elastomer (TPE) film and a substrate operates employs a surface contact bond between the TPE and a wall of the channel. Thermomechanical release of the valve, tristate functionality, and repeated semi-permanent closure and release are demonstrated.

Abstract: Magnetic nanoparticles are provided that have a superparamagnetic core and a nanoporous silica shell surrounding the core. The shell is functionalized with amine or S-nitrosothiol groups both inside and outside the nanopores. A process to provide such nanoparticles involves hydrolyzing tetraethoxysilane (TEOS) in a microemulsion of a superparamagnetic nanoparticle to form a superparamagnetic nanoparticle encapsulated by an incompletely hydrolyzed nanoporous silica shell, and hydrolyzing an amine-containing compound or a thiol-containing compound in situ in the presence of the incompletely hydrolyzed nanoporous silica shell before hydrolysis and densification of the silica shell is complete to functionalize the nanoporous silica shell with amine or thiol groups both inside and outside the nanopores and to maintain nanoporosity of the shell.

Abstract: A system and method for molecule detection uses a surface plasmon resonance (SPR) system with detection spots having fixed nanostructures. An SPR assembly may be combined with a digital microfluidic control system such as an electrowetting-on-dielectric (EWOD) chip. The microfluidic system individually directs sample droplets to different detection spots of the SPR assembly, thus allowing the SPR examination of different samples or sample reactions on the same surface. The nanostructures at the detection spots enhance the sensitivity of the SPR signals.

Abstract: A microfluidic system for processing a sample includes a microfluidic CD in the form a rotatable disc, the disc containing a plurality of separate lysis chambers therein. A magnetic lysis blade and lysis beads are disposed in each of the lysis chambers and a plurality of stationary magnets are disposed adjacent to and separate from the microfluidic CD. The stationary magnets are configured to magnetically interact with each of the magnetic lysis blades upon rotation of the microfluidic CD. Each lysis chamber may have its own separate sample inlet port or, alternatively, the lysis chambers may be connected to one another with a single inlet port coupled to one of the lysis chambers. Downstream processing may include nucleic acid amplification using thermoelectric heating as well as detection using a nucleic acid microarray.

Abstract: Glass as a substrate for fluorescence-based assays is expensive. Disclosed is a poly(cyclic olefin) alternative to glass that is of comparable sensitivity. More specifically, disclosed is a method of making a microdevice for the immobilization of biomolecules for the purpose of carrying out a fluorescence-based assay, said method comprising providing a substrate comprising a poly(cyclic olefin); protecting the substrate from ultraviolet (UV) light; and subjecting a surface of said UV-protected substrate to ozone oxidation to activate said surface; wherein a content of intrinsic fluorophores on the surface of the substrate remains substantially unchanged after the ozone oxidation.

Abstract: A method of detecting a fluorescence signal emitted by fluorophores bound to particles confined in a particle trap, includes an objective lens having a focal plane, which is normally the focal plane for incident collimated light. The particle trap is typically located in the focal plane, and a beam of excitation light is directed via the objective lens onto the confined particles in the trap. The excitation light is in the form of a divergent beam coming to focus at a plane displaced from the focal plane. The divergent beam has a spot diameter at the focal plane determined by the divergence of the beam. The fluorescent light emitted by the fluorophores is detected with a confocal detector.

Abstract: A microfluidic system for processing a sample includes a microfluidic CD in the form a rotatable disc, the disc containing a plurality of separate lysis chambers therein. A magnetic lysis blade and lysis beads are disposed in each of the lysis chambers and a plurality of stationary magnets are disposed adjacent to and separate from the microfluidic CD. The stationary magnets are configured to magnetically interact with each of the magnetic lysis blades upon rotation of the microfluidic CD. Each lysis chamber may have its own separate sample inlet port or, alternatively, the lysis chambers may be connected to one another with a single inlet port coupled to one of the lysis chambers. Downstream processing may include nucleic acid amplification using thermoelectric heating as well as detection using a nucleic acid microarray.

Abstract: A composition made of at least 60 wt. % of a thermoplastic elastomer resin and additives that are solid at least from 0-50° C., that has a Shore A hardness that is less than about 50 bears a patterned surface, the pattern comprising at least one microfluidic channel having a cross-sectional dimension smaller than 100 microns is a substrate for forming a microfluidic device. The chief advantages of such compositions are: its ability to bond in a sealing manner to smooth surfaces of many different compositions, its ease of manufacture and microstructure patterning, and its general impermeability to liquids.

Abstract: A system and method for molecule detection uses a surface plasmon resonance (SPR) system with detection spots having fixed nanostructures. An SPR assembly may be combined with a digital microfluidic control system such as an electrowetting-on-dielectric (EWOD) chip. The microfluidic system individually directs sample droplets to different detection spots of the SPR assembly, thus allowing the SPR examination of different samples or sample reactions on the same surface. The nanostructures at the detection spots enhance the sensitivity of the SPR signals.