Abstract: A technique is provided for incorporating pneumatic control in centrifugal microfluidics. The technique involves providing a chip controller that has pressurized fluid supply lines for coupling one or more pressurized chambers of the controller with ports of a microfluidic chip. At least part of the chip controller is mounted to a centrifuge for rotation with the chip. A flow control device is provided in each supply line for selectively controlling the pressurized fluid supply, and is electrically controlled. Bubble mixing, on and off-chip valving, and switching are demonstrated.

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: Gravitational Janus microparticle having, a center-of-mass, a center-of-volume, and a non¬uniform density, wherein: the center-of-mass and the center-of-volume are distinct. When suspended in a fluid, the microparticle substantially aligns with either: i) the gravitational field; or ii) the direction of an acceleration, such that the Janus microparticle is in substantial rotation equilibrium. After perturbation from substantial rotational equilibrium, the Janus microparticle reversibly rotates to return to substantial rotational equilibrium. The gravitational Janus microparticle may comprise at least two portions, each having distinct physical and/or chemical characteristics, wherein at least one portion provides a detectable effect following rotation and alignment of the microparticle.

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: Described are various embodiments of a method for fabricating a polymer membrane having open through holes, and membranes so produced. In some embodiments, a curable polymeric resin is introduced within a micro post structure wherein a material of the micro posts is soluble in a solvent and wherein the curable polymeric resin is insoluble in this solvent such that the structure can be at least partially dissolved to release the membrane once cured.

Abstract: A patterned thermoplastic elastomer (TPE) film for fabricating a liquid-filled blister, has a blister-sized cavity in fluid communication with a microfluidic channel via a gating region.

Abstract: A security device comprising a microstructure and one or more curable fluids, in which the microstructure is configured to direct the one or more curable fluids from a local application zone of the microstructure to one or more regions of the microstructure prior to curing each curable fluid. Alternatively, the security device may comprise a microstructure; and one or more cured fluids; in which each cured fluid is derived from a corresponding curable fluid that is directed by the microstructure from a local application zone of the microstructure to one or more regions of the microstructure prior to curing each curable fluid. The microstructure can have a depth of at least 100 nm, and a spacing aspect ratio (depth to height) greater than 1:10. A process for fabricating a security device is also described.

Abstract: Gravitational Janus microparticle having, a center-of-mass, a center-of-volume, and a non-uniform density, wherein: the center-of-mass and the center-of-volume are distinct. When suspended in a fluid, the microparticle substantially aligns with either: i) the gravitational field; or ii) the direction of an acceleration, such that the Janus microparticle is in substantial rotation equilibrium. After perturbation from substantial rotational equilibrium, the Janus microparticle reversibly rotates to return to substantial rotational equilibrium. The gravitational Janus microparticle may comprise at least two portions, each having distinct physical and/or chemical characteristics, wherein at least one portion provides a detectable effect following rotation and alignment of the microparticle.

Abstract: A security device that elicits at least one dynamic response upon acceleration, or upon change of orientation with respect to gravity, wherein the dynamic response continues after cessation of the acceleration or the change of orientation. In addition, the dynamic response can be optical, such that it is visually observable by an unaided human eye. Alternatively, the response can be machine readable. In some cases, the dynamic response has duration of from about 0.01 s to about 100 s, or from about Is to about 10 s.

Abstract: A smart ink, comprising microparticles, with each microparticle comprising: a) an exterior shell; b) a liquid encapsulated within the shell; and c) a Janus microparticle suspended in the liquid, wherein the Janus microparticle either comprises: i) two or more distinct assemblies of particles; or ii) a core loaded with particles, the core having a first surface portion and a second surface portion that is functionally distinct from the first surface portion. An apparatus and method for production of the microparticles are also provided.

Abstract: A patterned thermoplastic elastomer (TPE) film for fabricating a liquid-filled blister, has a blister-sized cavity in fluid communication with a microfluidic channel via a gating region.

Abstract: A centrifugal microfluidic chip mounting, kit and method include a swivel joint permitting a chip to rotate about an axis of the chip in a plane swept by a centrifuge, and a force applicator for controlling an angle of the swivel and for applying a force in proportion to a rotational rate of the centrifuge. The mounting includes: a blade part (18) that couples to, or defines, a blade (10) of a centrifuge at a radial distance from a centrifuge axis (12); a chip part (20) that holds the chip at an orientation having a normal not perpendicular to the axis; a one degree of freedom (DoF) joint (16) between the blade part and the chip part; and a force applicator (28) which bears on the chip part at a fixed set of one or more points, which do not surround, and are not surrounded by, the joint.

Abstract: A technique is provided for incorporating pneumatic control in centrifugal microfluidics. The technique involves providing a chip controller that has pressurized fluid supply lines for coupling one or more pressurized chambers of the controller with ports of a microfluidic chip. At least part of the chip controller is mounted to a centrifuge for rotation with the chip. A flow control device is provided in each supply line for selectively controlling the pressurized fluid supply, and is electrically controlled. Bubble mixing, on and off-chip valving, and switching are demonstrated.

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: 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: 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 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 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 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 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.