Abstract: Dielectrophoretic (DEP) tweezers apparatus and methods for various applications, including particle trapping. Two electrodes are disposed on or otherwise constitute an elongated object forming a tip. A voltage is applied across these electrodes to produce a non-uniform electromagnetic field proximate to the tip thereby creating a dielectrophoretic trap. Once trapped, a particle may be moved to desired locations via manipulation of the elongated object or the medium in which the particle is located. Multiple DEP tweezers apparatus may be arranged to form arrays of tips capable of respectively generating local electromagnetic fields confined to the tips. Such DEP arrays may be employed in nanofabrication processes involving nanolithography or nano-manipulation, as well as data storage and retrieval applications.

Abstract: The present invention relates to a method and an apparatus for the characterization and/or the counting of particles by means of non uniform, time variable force fields and integrated optical or impedance meter sensors. The force fields can be of positive or negative dielectrophoresis, electrophoresis or electro-hydrodynamic motions, characterized by a set of stable equilibrium points for the particles (solid, liquid or gaseous); the same method is suitable for the manipulation of droplets (liquid particles) by exploiting effects known to the international scientific community with the name of Electro-wetting on dielectric.

Abstract: Dielectrophoretic (DEP) tweezers apparatus and methods for various applications, including particle trapping. Multiple electrodes (e.g., two or three) are disposed on or otherwise constitute an elongated object forming a tip. Exemplary electrode configurations include, but are not limited to, coaxial and triaxial arrangements. A voltage is applied across these electrodes to produce a non-uniform electromagnetic field proximate to the tip thereby creating a dielectrophoretic trap. Once trapped, a particle may be moved to desired locations via manipulation of the elongated object or the medium in which the particle is located. Multiple DEP tweezers apparatus may be arranged to form arrays of tips capable of respectively generating local electromagnetic fields confined to the tips. Such DEP arrays may be employed in nanofabrication processes involving nanolithography or nano-manipulation, as well as data storage and retrieval applications.

Abstract: A continuous periodic electric wave electrophoresis device and method generates a continuous periodic electric wave that electrophoretically separates charged particles within a sample. The device can have a channel wherein the sample is introduced. At least three interdigitated arrays of conducting electrodes can be positioned adjacent the channel with each array having an externally controllable electrical potential. An externally controlled electric current can be applied to each array of conducting electrodes, creating a continuous periodic electric wave having a selectable wave speed within the channel that separates the particles within the sample. The continuous periodic electric wave can entrain high-mobility particles and immobilize low-mobility particles.

Abstract: Method and apparatus for the manipulation and/or control of the position of particles by means of time-variable fields of force. The fields of force can be of dielectrophoresis (positive or negative), electrophoresis, electrohydrodynamic or electrowetting on dielectric, characterized by a set of stable points of equilibrium for the particles.

Abstract: Systems and methods for separating particles and/or toxins from a sample fluid. A method according to one embodiment comprises simultaneously passing a sample fluid and a buffer fluid through a chamber such that a fluidic interface is formed between the sample fluid and the buffer fluid as the fluids pass through the chambers the sample fluid having particles of interest therein; applying a force to the fluids for urging the particles of interest to pass through the interface into the buffer fluid; and substantially separating the buffer fluid from the sample fluid.

Abstract: A one-piece, microfluidic package with standardized multiple ports allows devices to be connected in series without resorting to extra tubing connections or bonding processes. The one-piece construction consists of microfluidic channels that can be connected to fluid reservoirs and other fluidic components fabricated with interconnecting and interlocking ports. The size of the friction-fit interlocking ports is designed such that the smaller male port fits snugly into the larger female port in a manner that is leak-free and adhesive-free. The friction-fit ports can also be reconfigured. Thus, the interconnection of microfluidic packages can be in an extended series including connections to sensors and devices such as a bio/biochemical/chemical sensor chip, a dielectrophoretic manipulator chip, and a microfluidic reactor chip.

Abstract: An optical image-driven light induced dielectrophoresis (DEP) apparatus and method are described which provide for the manipulation of particles or cells with a diameter on the order of 100 ?m or less. The apparatus is referred to as optoelectric tweezers (OET) and provides a number of advantages over conventional optical tweezers, in particular the ability to perform operations in parallel and over a large area without damage to living cells. The OET device generally comprises a planar liquid-filled structure having one or more portions which are photoconductive to convert incoming light to a change in the electric field pattern. The light patterns are dynamically generated to provide a number of manipulation structures that can manipulate single particles and cells or groups of particles/cells. The OET preferably includes a microscopic imaging means to provide feedback for the optical manipulation, such as detecting position and characteristics wherein the light patterns are modulated accordingly.

Abstract: Devices for the manipulation of a suspended particle in an electric field gradient include a plurality of electrically isolated electrodes on a surface. A liquid composition is on the plurality of electrodes. The liquid composition covers the surface continuously between adjacent ones of the plurality of electrodes. The liquid composition has an exposed liquid surface for suspending a particle. The plurality of electrodes are configured to provide an electric field gradient for transporting the particle suspended in said liquid composition.

Abstract: The invention relates to a micro-fluidic system including a fluid medium channel that holds a fluid medium containing particles in suspension. According to the invention, the fluid medium channel has an expanded section with an enlarged cross-section along part of its length, in order to reduce the flow speed to allow the analysis of the particles.

Abstract: An apparatus for extracting and concentrating bioagents within a continuously flowing fluid medium includes a flow channel fluid inlet, in which bioagents are concentrated from three dimensions to a two-dimensional transport layer in a preconcentration area. Traveling wave grids cause the preconcentrated bioagents to migrate to one side of the flow channel and then to an extraction port. Each of the traveling wave grids includes a substrate, a collection of closely spaced and parallel electrically conductive electrodes extending across said substrate, and a collection of buses providing electrical communication with the collection of conductive electrodes. A voltage controller provides a multiphase electrical signal to the collection of buses and electrodes of the traveling wave grids. Fluid exits through an outlet port.

Abstract: This paper presents a microfluidic pumping approach using traveling-wave dielectrophoresis (tw-DEP) of microparticles. Flow is generated directly in the microfluidic devices by inducing electromechanical effects in the fluid using microelectrodes. The fluidic driving mechanisms due to the particle-fluid and particle-particle interactions under twDEP are analyzed, and the induced flow field is obtained from numerical simulations. Experimental measurements of the flow velocity in a prototype DEP micropumping device show satisfactory agreement with the numerical predications.

Abstract: Disclosed are example methods and devices for detecting one or more targets. An example method includes placing a sample including a first target with in a microfluidic device and hybridizing a plurality of copies of the first target with a plurality of nanostructures. The example method includes applying an electric current to the plurality of nanostructures and using an electric field created by the electric current to move the plurality of nanostructures. In addition, the plurality of nanostructures are sorted and evaluated to determine at least one of a presence, an absence, or a quantity of the first target.

Abstract: The invention provides apparatus and methods for arraying particles on a surface using dielectrophoresis.

Abstract: Plural types of cells having different dielectrophoretic properties are separated using a simple structure. There is provided a cell separation device including: a flow path through which a cell suspension flows, the cell suspension containing plural types of cells which have different dielectrophoretic properties; electrodes disposed to face each other in a direction intersecting a flow direction of the cell suspension flowing in the flow path; an electric field gradient forming portion which generates an electric field strength gradient between the electrodes; and a power supply applying an alternating voltage having a direct current component across the electrodes.

Abstract: Disclosed herein are methods and devices for assaying and concentrating analytes in a fluid sample using dielectrophoresis. As disclosed, the methods and devices utilize substrates having a plurality of pores through which analytes can be selectively prevented from passing, or inhibited, on application of an appropriate electric field waveform. The pores of the substrate produce nonuniform electric field having local extrema located near the pores. These nonuniform fields drive dielectrophoresis, which produces the inhibition. Arrangements of electrodes and porous substrates support continuous, bulk, multi-dimensional, and staged selective concentration.

Abstract: A device for transporting and focusing ions in a low vacuum or atmospheric-pressure region of a mass spectrometer is constructed from a plurality of longitudinally spaced apart electrodes to which oscillatory (e.g., radio-frequency) voltages are applied. In order to create a tapered field that focuses ions to a narrow beam near the device exit, the inter-electrode spacing or the oscillatory voltage amplitude is increased in the direction of ion travel.

Abstract: A portable apparatus for extracting and concentrating bioagents within a fluid medium includes a container with sample solution inlet port and traveling wave grids patterned on surfaces of the container. The traveling wave grids cause bioagents to migrate to a specified surface within the container and then to an extraction port. The traveling wave grids include a substrate, across which extend a collection of closely spaced and parallel electrically conductive electrodes, and a collection of buses providing electrical communication with the collection of conductive electrodes. A voltage controller provides a multiphase electrical signal to the collection of buses and electrodes of the traveling wave grids.

Abstract: Detail is apparatus for collecting particles from a liquid, including a first electrode having an upper surface defining one or more substantially circular areas of a predetermined diameter separated from a counter electrode, having an uppersurface bounding at least in part the circular area or areas of the first electrode, by a predetermined gap and equipment for applying an alternating potential difference of a predetermined magnitude at a predetermined frequency lower than the charge relaxation frequency of the liquid across the electrodes whereby particles from the liquid are focused onto the circular area or areas of the first elect through an induced electro-osmotic flow in the liquid.

Abstract: A particle separator for separating different types of particles with different properties includes a channel unit including a flow channel through which a first fluid having particles with at least one physical characteristic and a second fluid that flows near the first fluid, and a plurality of outflow channels that are connected to the flow channel and that separate the fluid having passed the flow channel; and a field forming unit, installed adjacent to the flow channel, for separating the particles included in the first fluid from the first fluid and generating a non-uniform field so that the particles may flow together with the second fluid.

Abstract: Systems, devices, and methods are presented that facilitate electronic manipulation and detection of submicron particles. A particle manipulation device contains a plurality of electrodes formed on an active semiconductor layer of an integrated circuit chip, where the electrodes and gap spacing between adjacent electrodes is submicron in size. The chip is oriented with its substrate face up, and at least a portion of the substrate is removed from the chip so the electrodes are in close proximity to a fluid chamber(s) placed over the chip, to facilitate manipulation of particles, contained in a buffer solution in the fluid chamber(s), to form a defined pattern. Innovative macro-scale optical detection is employed to detect the submicron particles, where a light beam is applied to the defined pattern, and interaction of the defined pattern with the light beam is detected and evaluated to facilitate detecting the particles.

Abstract: The invention relates to a microfluidic system containing a carrier current channel (1) for receiving a carrier current containing particles suspended therein, and at least one electrode arrangement (3) which is arranged in the carrier current channel and used to manipulate the suspended particles (2), the electrode arrangement (3) containing two manipulation electrodes (4, 5). According to the invention, the electrode arrangement (3) contains two centering electrodes (6, 7), in addition to the two manipulation electrodes (4, 5), for centering the particles, the two centering electrodes (6, 7) being arranged in the carrier current channel (1) respectively upstream of one of the two manipulation electrodes (4, 5). The invention also relates to a corresponding control method.

Abstract: Disclosed is a device for separating and concentrating particles suspended in a fluid stream by using dielectrophoresis (DEP) to trap and/or deflect those particles as they migrate through a fluid channel. The method uses fluid channels designed to constrain a liquid flowing through it to uniform electrokinetic flow velocities. This behavior is achieved by connecting deep and shallow sections of channels, with the channel depth varying abruptly along an interface. By careful design of abrupt changes in specific permeability at the interface, an abrupt and spatially uniform change in electrokinetic force can be selected. Because these abrupt interfaces also cause a sharp gradient in applied electric fields, a DEP force also can be established along the interface.

Abstract: The present invention provides methods for enhancing the efficiency of cell electroporation using dielectrophoresis-assisted cell localization and uses thereof in a microfluidic biochip system. Cells are first subject to dielectrophoresis and localized to regions where the electric field intensity is high enough to render cells electroporated. The invention enhances the efficiency of in situ cell electroporation on a traditional microfluidic biochip.

Abstract: The present invention is directed to the use of dielectrophoretic forces for the arbitrary manipulation of micrometer- and nanometer-sized particles and to devices capable of arbitrarily manipulating micrometer- and nanometer-sized particles by means of dielectrophoretic forces within a two- or three-dimensional region. The devices and methods of the invention are capable of arbitrarily controlling the velocities, locations, and forces applied to a particle, arbitrarily specifying a force or set of forces at a location in space, and determining friction and/or drag coefficients of a particle, and are thus well-suited for a range of applications including cell sorting, drug delivery, as a diagnostic tool for determining membrane stiffness, and in the heterogeneous integration of micro- and nano-components through directed assembly.

Abstract: The present invention provides a device and methods of use thereof in microscale cell sorting. This invention provides sorting cytometers, which trap individual cells within vessels following exposure to dielectrophoresis, allow for the assaying of trapped cells, such that a population is identified whose isolation is desired, and their isolation.

Abstract: Described is a fluidic microsystem (100) including at least one channel (10) through which a particle suspension can flow; and first and second electrode devices (40, 60) which are arranged on first and second channel walls (21, 31) for generating electrical alternating-voltage fields in the channel (10); wherein the first electrode device (40) for field shaping in the channel includes at least one first structure element (41, 51); and the second electrode device (60) includes an area-like electrode layer (61) with a closed second electrode surface which includes a second passivation layer (70); wherein the effective electrode surface of the first structure element (41, 51), of which element (41, 51) there is at least one, is smaller than the second electrode surface; and the second passivation layer (70) is a closed layer which completely covers the second electrode layer (61).

Abstract: Methods, devices, and systems for separating disparate liquid-suspended particles in a flow channel using dielectrophoresis induced by concave-shaped electrodes and field-flow fractionation.

Abstract: Methods, devices, and systems for separating a time-varying flow of disparate liquid-suspended particles through a channel using dielectrophoresis and field-flow fractionation.

Abstract: A process and a device for retaining polarizable target-particles from a fluid suspension of polarizable target-particles comprising the steps of pumping that suspension into a vertical or inclined channel and applying an alternating electric field inducing a negative dielectrophoretic force on the target-particles, the force being sufficient to push them a distance of at least or about 25 m from the surface of an electrode-bearing wall, thereby creating an upward-moving clarified fluid zone in the vicinity of that wall and a downward-moving target-particle containing fluid zone at a distance from that wall.

Abstract: A microfluidic liquid stream configuration system is provided including providing a substrate; forming a first co-planar electrode and a second co-planar electrode on the substrate; applying a dielectric layer, with a controlled surface energy, on the first co-planar electrode and the second co-planar electrode; forming an input reservoir on the first co-planar electrode and a second co-planar electrode; supplying a liquid in the input reservoir for analysis; and imposing an electric field, an electric field gradient, or a combination thereof on the liquid for respectively driving surface charge or dipole moments in the liquid for configuring a liquid stream.

Abstract: A microscale biosensor for use in the detection of target biological substances includes a detection chamber disposed on the substrate and defining a volume between 1 pico-liter and 1 micro-liter. The detection chamber is adapted to confine a composition containing microorganisms. Specimen concentration componentry is connected to the detection chamber for rapidly concentrating the microorganisms in the detection chamber. A heater is operatively connected to the substrate to heat the composition in the detection chamber. Electrodes are mounted on the substrate in communication with the detection chamber to identify AC impedance changes within the detection chamber from bacterial metabolism of the microorganisms of the composition over time.

Abstract: The present invention provides a device and methods of use thereof in microscale cell sorting. This invention provides sorting cytometers, which trap individual cells within vessels following exposure to dielectrophoresis, allow for the assaying of trapped cells, such that a population is identified whose isolation is desired, and their isolation.

Abstract: A method is provided for classifying nanoobjects having different electrical properties, such as conductivities and permittivities. The method includes: suspending nanoobjects having different electrical properties in a liquid medium; passing the liquid medium through a microchamber; and filtering nanoobjects having a first type of electrical property from the liquid medium by applying an electric field to the liquid medium in the microchamber.

Abstract: Microfluidic devices according to embodiments of the present invention include an inlet port, an outlet port, and a channel or chamber having a non-uniform array of insulating features on one or more surfaces. Electrodes are provided for generation of a spatially non-uniform electric field across the array. A voltage source, which may be an A.C. and/or a D.C. voltage source may be coupled to the electrodes for the generation of the electric field.

Abstract: The invention provides a microfabricated device for sorting cells based on a desired characteristic, for example, reporter-labeled cells can be sorted by the presence or level of reporter on the cells. The device includes a chip having a substrate into which is microfabricated at least one analysis unit. Each analysis unit includes a main channel, having a sample inlet channel, typically at one end, and a detection region along a portion of its length. Adjacent and downstream from the detection region, the main channel has a discrimination region or branch point leading to at least two branch channels. The analysis unit may further include additional inlet channels, detection points, branch points, and branch channels as desired. A stream containing cells is passed through the detection region, such that on average one cell occupies the detection region at a given time.

Abstract: Embodiments of the invention are directed to apparatus, methods, and applications involving the actuation of a semi-insulative working fluid by electromechanical forces based on electrowetting-on-dielectric (EWOD) and liquid dielectrophoresis (liquid DEP) mechanisms that are controlled by the frequency, but not the magnitude, of an AC voltage (i.e., ‘frequency-addressable). In the various apparatus embodiments of the invention, a single, frequency-addressable electrode pair includes at least one electrode that has a spatially-varying dielectric coating thickness and thus a spatially-varying electrode gap wherein at least a portion of which a volume of a working fluid can stably reside under no influence of an applied voltage. In an exemplary aspect, a frequency-addressable, bistable apparatus includes at least one wider gap and one narrower gap associated, respectively, with a thicker and a thinner dielectric coating thickness of the electrode(s).

Abstract: The invention relates to a method for generating a convective liquid motion in a fluidic microsystem. According to this method, a liquid in a microsystem is simultaneously exposed to an electrical field and a thermal gradient. The electrical field is generated by means of an electrode arrangement which is subjected to a time-variant voltage. In this way, a time variant electrical field is formed in the liquid volume. The thermal gradient is produced by means of at least one radiation absorber located in the compartment which is exposed to at least one external radiation field.

Abstract: A method of sorting cells for a biodevice comprises directing a flow of cells within a fluid into a filtration structure defining an array of fluid openings and encouraging cell passage of each cell of a portion of the cells through the fluid openings based on at least one dimension of each cell via application of an electric field within the fluid openings.

Abstract: A method of sorting cells comprises providing a fluid flow path for cell movement through a series of cell sorters in a first direction with an output of a preceding cell sorter of the series communicating with an input of a successive cell sorter of the series. Within each cell sorter, a first portion of the cells is separated from a second portion of the cells by applying a first non-uniform electric field via a first electrode array to cause movement of the first portion of the cells in a second direction across the fluid flow path, having a component generally transverse to the first direction into the output of a respective cell sorter.

Abstract: Surface 12's hydrophobic region 26 is surrounded by hydrophilic region 28. Hydrophobic region 26 is coated with first electrical insulator fluid 10 (e.g. oil). Surface 12 and first fluid 10 are submerged in second fluid 14 (e.g. water) having a high dielectric constant value relative to the first fluid's dielectric constant value and/or having non-zero electrical conductivity. An electric field is selectably applied between second fluid 14 and spaced-apart sections of hydrophobic region 26 to form compact volume portions 10A, 10B of first fluid 10 between the spaced-apart sections. Elongated volume portions of first fluid 10 remain on the spaced-apart sections of hydrophobic region 26, fluidicly interconnecting compact volume portions 10A, 10B. If the electric field is sequentially applied to different sections of hydrophobic region 26 during successive time intervals the compact and elongated volume portions of first fluid 10 are redistributed moved to different sections of hydrophobic region 26.

Abstract: The equipment of the present invention can implement high-speed hybridization with a simple construction and is configured as described below. The equipment comprises a biochip prepared by fixing biopolymers onto a plurality of sites on a substrate, positive and negative electrodes for generating an electric field along the surface of this biochip substrate, and a magnetic field generating means for generating a magnetic field along the surface of the above biochip substrate, and is configured to move biopolymers movable in the fluid stored over the above-mentioned biochip substrate along the surface of the above biochip substrate as well as to attract the above described biopolymers towards the surface of the above biochip substrate during hybridization of the above biopolymers, by making the above-mentioned electric and magnetic fields act along the surface of the above biochip substrate.

Abstract: A method of analyzing blood includes delivering a blood sample to a test device, applying a spatially varying electric field to the blood sample to provide a depleted cell concentration in a portion of the blood sample, and sensing a property of the portion of the blood sample.

Abstract: Devices are provided for separating and focusing charged analytes, comprising a separation chamber and two or more electrodes, for example, an electrode array. A membrane separates the separation chamber and the electrodes. The separation chamber of the device is configured, that is, the separation chamber has a shaped geometry, which serves to induce a gradient in an electric field generated by the electrodes in the electrode chamber. Optionally, molecular sieve is included in the separation chamber that is operative to shift the location at which a stationary focused band of a charged analyte forms under a given set of focusing process parameters. Methods are provided for separating and focusing charged analytes comprising introducing a first fluid comprising at least one charged analyte into the separation chamber of a device as just described, applying an electric field gradient to the charged analyte to focus the charged analyte in the electric field gradient.

Abstract: Embodiments of the present invention provide methods and devices for manipulating particles using dielectrophoresis. Insulating ridges and valleys are used to generate a spatially non-uniform electrical field. Particles may be concentrated, separated, or captured during bulk fluid flow in a channel having insulating ridges and valleys.

Abstract: Method and Systems for extracting a concentrated sample of particles include priming a concentrate reservoir by passing a fluid through the concentrate reservoir to remove air. The concentrate reservoir has a first end with an opening and second end with an opening. The second end of the concentrate reservoir is closed off, and particles are accumulated within the concentrate reservoir by use of a particle concentrator. Thereafter, the first end of the concentrate reservoir is closed off, isolating the concentrate reservoir from particle concentrator, from which the particles were obtained. The second end of the concentrate reservoir is thereafter opened, and the particles of the concentrated sample in the concentrate reservoir are extracted to a sample capture reservoir through the second end opening of the concentrate reservoir.

Abstract: Various traveling wave grids and related systems are disclosed that are particularly beneficial for the separation, transport, and focusing of biomolecules or other charged species. An implementation of a vertically integrated traveling wave module is described which allows for scalability to arbitrary gel dimensions through tiling. In addition, several unique traveling wave algorithms are also described which when used in conjunction with the traveling wave grids, impart selective motion to biomolecules or other charged species.

Abstract: A method for collecting a microbiological substance utilizes a micro fabricated biochip having a collection chamber. A fluid sample containing a microbiological entity of interest is delivered to the collection chamber in the biochip. Then a non-uniform electric field is generated in the collection chamber, to retain the microbiological entity of interest in the collection chamber. The microbiological entity is retained through dielectrophoresis induced by the energization of the electrodes by a periodically applied, alternating current.

Abstract: A system for transporting and selectively sorting particles includes a first wall and a traveling wave grid extending along the first wall. The system includes a second wall having a passage extending therethrough and a gate operatively associated with the passage. A controller is adapted to output a multi-phase electrical signal. The controller is in communication with the traveling wave grid and the gate. A method of using the system is also provided.

Abstract: Microtechnologically prepared component as a flow cytometer. The component contains a preparation area to specifically influence and separate the particles, preferably by dielectrophoresis, a measuring channel area for characterizing the particles, and a sorting area for sorting the particles identified in the measuring channel area by dielectrophoresis. The sorting includes switching elements which permit active guidance of the particles into two or more subchannels corresponding to the criteria which have been registered in the measuring channel area. With a component configured in this way for the use of a flow cytometer, quick and precise sorting of particles, in particular biological cells in a suspension, can be implemented.