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: Described is a fluidic microsystem with at least one compartment for the receiving and/or the through-flow of a liquid and having an electrode arrangement with a multiplicity of electrodes, between which a coaction zone is established, whereby the compartment possesses at least one wall, through which electromagnetic radiation can be linked into the said coaction zone in accord with a predetermined incident direction, and on at least one electrode a cooling apparatus is provided, and on which at least one respective electrode at least one reflector layer is provided, and wherein the respective electrode is at least partially shielded in reference to the incident beam direction, and having at least one heat conducting layer by means of which the respective electrode stands in thermal communication with a wall of the compartment, and/or includes an active cooling element, which is placed in thermal contact with the respective electrode.

Abstract: A description is given of methods for collecting particles (1, 2) which are suspended in a liquid, including the following steps: providing the liquid containing the suspended particles (1, 2) in a compartment (10) having lateral surfaces (11), wherein at least one electrode (21) is arranged on at least one of the lateral surfaces (11), and generating high-frequency electric fields by means of the at least one electrode (21) so as to form at least one circulating flow (30), by means of which the particles (1, 2) are guided to at least one predetermined collecting area (40) in the compartment (10), wherein the flow (30) is formed in such a way that at least one branch of the flow runs along a longitudinal extent of the at least one electrode (21), and the flow (30) circulates about an axis (31) which is oriented perpendicular to the respectively adjacent lateral surface (11) with the electrode (21). Corresponding devices for collecting particles are also described.

Abstract: The invention relates to a microfluidic system, in particular in a cell sorter, including a first carrier power supply (1) which is used to supply a first carrier flow having particles (4) suspended therein, a first carrier power output line (15) which is used to withdraw at least one part of the carrier flow having particles (4) suspended therein, a process chamber (3) which is used to examine, observe, manipulate and/or select the particle (4). The first carrier power supply (1) flows into the process chamber (3) when the first carrier power output line (15) is discharged from the process chamber (3). According to the invention, at least one second carrier power supply (2) flows into the process chamber (3) in order to supply a second carrier flow having particles (5) suspended therein. The invention also relates to a corresponding operational method.

Abstract: The invention relates to a microfluidic system, in particular in a cell sorter, including a first carrier power supply (1) which is used to supply a first carrier flow having particles (4) suspended therein, a first carrier power output line (15) which is used to withdraw at least one part of the carrier flow having particles (4) suspended therein, a process chamber (3) which is used to examine, observe, manipulate and/or select the particle (4). The first carrier power supply (1) flows into the process chamber (3) when the first carrier power output line (15) is discharged from the process chamber (3). According to the invention, at least one second carrier power supply (2) flows into the process chamber (3) in order to supply a second carrier flow having particles (5) suspended therein. The invention also relates to a corresponding operational method.

Abstract: A plurality of planar electrodes (5) in a microchannel (4) is used for separation, lysis and PCR in a chip (10). Cells from a sample are brought to the electrodes (5). Depending on sample properties, phase pattern, frequency and voltage of the electrodes and flow velocity are chosen to trap target cells (16) using DEP, whereas the majority of unwanted cells (17) flushes through. After separation the target cell (16) are lysed while still trapped. Lysis is carried out by applying RF pulses and/or thermally so as to change the dielectric properties of the trapped cells. After lysis, the target cells (16) are amplified within the microchannel (4), so as to obtain separation, lysis and PCR on same chip (1).

Abstract: Methods are described for analyzing at least one deformable object (O) in a suspension fluid, including the following steps: generation of an electric positioning field and positioning of the object (O) in a potential minimum of the positioning field, generation of an electric deformation field in such a way that a deformation force is exerted on the object (O), and detection of at least one property selected from the group including the dielectric, geometric and optical properties of the object (O), wherein the positioning field is generated in a compartment (12) of a fluidic microsystem (10) and the positioning of the object (O) takes place in a contactless manner in a freely suspended state. Measuring apparatuses for carrying out this method are also described.

Abstract: Processes are described for the treatment of at least one particle (10-13) with at least one reaction liquid (20) in a main channel (30) of a fluidic microsystem (100) with the following steps: movement of the at least one particle (10-13) with a carrier liquid (40) flowing in a longitudinal direction of the main channel (30) up to a holding device (50), at least a temporary holding of the at least one particle (13) under the action of a holding force exerted by the holding device (50), and supplying of the reaction liquid (20) from at least one lateral channel (31) into the main channel (30) so that the at least one held particle (13) is rinsed by the reaction liquid (20), the holding device (50) being arranged downstream after a mouth (32) of the lateral channel (31) in the main channel (30) and the reaction liquid (20) flowing through the holding device (50) with a direction of flow running in the longitudinal direction of the main channel (30).

Abstract: Methods and devices for the separation of particles (20, 21, 22) in a compartment (30) of a fluidic microsystem (100) are described, in which the movement of a liquid (10) in which particles (20, 21, 22) are suspended with a predetermined direction of flow through the compartment (30), and the generation of a deflecting potential in which at least a part of the particles (20, 21, 22) is moved relative to the liquid in a direction of deflection are envisaged, whereby further at least one focusing potential is generated, so that at least a part of the particles is moved opposite to the direction of deflection relative to the liquid by dielectrophoresis under the effect of high-frequency electrical fields, and guiding of particles with different electrical, magnetic or geometric properties into different flow areas (11, 12) in the liquid takes place.

Abstract: Described are a method and a measuring device for measuring the impedance in a fluidic microsystem comprising a compartment (10) through which a liquid comprising at least one suspended particle (16) flows, and in which at least one impedance detector (40) is arranged, by means of which for detection of the at least one particle at least one impedance value is acquired which is characteristic for the impedance of the compartment, and which in the presence of the at least one particle changes in a predetermined way, wherein focusing of the at least one particle takes place in a predetermined space relative to the impedance detector, wherein focusing involves a movement of the at least one particle relative to the fluid flowing in the compartment as a result of dielectrophoretic forces, which forces are exerted by means of at least two focusing electrodes (30).

Abstract: Disclosed is a method for measuring properties of particles that move through a fluidic microsystem, the particles being suspended in a liquid. According to the inventive method, a first parameter of a specific particle is first measured at a first test station (11). A second parameter of the particle is then measured at an interval from the first measurement at a second test station (12) which is spatially separated from the first test station (11), and the first and second parameters are jointly evaluated in a correlated manner, the first and second parameters being characteristic of different properties of the tested particle. The evaluation comprises a comparison of the first and second parameters with predetermined expected values. Another measurement is taken or manipulations are performed on the tested particle according to the result of the comparison. Also disclosed is a fluidic microsystem that is designed for implementing the inventive method.

Abstract: A microsystem adapted for dielectrophoretic manipulation of particles in a suspension liquid wherein the microsystem has a channel with channel walls and a longitudinal extension. An electrode arrangement is present which has at least one microelectrode on at least one of the channel walls. This acts to generate a field barrier which crosses the channel at least partly. The microelectrode has a band-shape or has a multitude of straight electrode sections connected to each other. The band-shape has a predetermined curvature or the straight electrode sections are arranged with predetermined different angles so that the field barrier has a predetermined curvature relative to the longitudinal extension of the channel.

Abstract: A method for high-resolution image recording of at least one object with a microscope, includes the steps of: (a) positioning the object in a receptacle being arranged in the optical axis of the microscope, (b) generating at least two first data sets per object which represent intermediate images of the object with at least two different orientations relative to the optical axis of the microscope, wherein the different orientations of the object are provided by moving the object relative to the receptacle, and (c) evaluating the data sets for obtaining quantitative three dimensional information.

Abstract: Described is a fluidic microsystem (100) comprising 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 comprises at least one first structure element (41, 51); and the second electrode device (60) comprises an area-like electrode layer (61) with a closed second electrode surface which comprises 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: To measure or exert optically-induced forces on at least one particle in the focus of an optical cage, the following steps are taken: a) the focus is positioned in a microelectrode arrangement with a three-dimensional electrical field that has a field gradient which forms an electrical capture area, and the focus is at a distance from the capture are and b) the amplitude of the electrical field, the light power of the light beam forming the optical cage, and/or the distance of the capture area from the focus are varied to detect which varied field property moves the particle from the focus to the capture area or vice versa, or at least to temporarily move the particle into the capture area.

Abstract: For object detection, particularly in fluidic microsystems, optical imaging of at least one resting or moving object (10) on a structured mask (20) with at least one segment from a flat section (80), in which the object (10) is located at least partially or temporarily and which has a characteristic dimension smaller than the dimension of the object (10) or its movement path, to a detector unit, detection of the quantity of light transmitted by the structured mask (20), and generation of a detector signal which has a predetermined relationship with the quantity of light, and evaluation of the detector signal in regard to the presence of the object (10), its position, its shape and/or the temporal change of the position are performed.

Abstract: Electrode arrangement (10) in a microsystem adapted for dielectrophoretic manipulation of particles (30) in a suspension fluid in a channel (21), wherein at least one electrode (11, 11a, 11b, 12) is arranged on a lateral wall of the channel (21), the electrode (11, 11a, 11b, 12) consisting of a plurality of electrode segments adapted to generate at least one field gradient for influencing the movement paths of the particles (30) in the channel (21). In one embodiment of the invention, the particles are moved in the microsystem by exposure to centrifugal and/or gravitational forces.

Abstract: To manipulate microparticles in a fluid that intersects a first channel or several first channels as a stream, one or more microparticles (14) are exposed to electrical field barriers that change their direction from the direction of flow toward the edge of the flow to a lateral hole (17) of the respective first channel. As a result, microparticles can be moved back and forth between streaming fluids. Preferred applications include treatment, separating, sorting or confinement procedures.

Abstract: Described is a fluidic microsystem (100) with at least one compartment (10) for the receiving and/or the through-flow of a liquid and having an electrode arrangement (20) with a multiplicity of electrodes (21-28), between which a coaction zone (11) is established, whereby the compartment (10) possesses at least one wall (12-14), through which electromagnetic radiation can be linked into the said coaction zone (11) in accord with a predetermined incident direction (B), and on at least one electrode (21-28) a cooling apparatus is provided, and on which at least one respective electrode (21-28) at least one reflector layer (21b, 22b, 25b, 26b, 26c, 21c) is provided, and wherein the respective electrode (21-28) is at least partially shielded in reference to the incident beam direction (B), and having at least one heat conducting layer (50) by means of which the respective electrode (21-28) stands in thermal communication with a wall of the compartment (10), and/or includes an active cooling element (21c), which i

Abstract: A method is described for non-destructive measurement of vitality of biological cells, especially for determination of apoptosis, in which the at least one cell is exposed to high-frequency alternating, especially rotating, electric fields and/or impedance test fields, and at least one rotation measurement, one dielectrophoresis measurement and/or one impedance measurement is performed with the cell for at least one frequency range or individual frequencies, from which at least one measurement parameter is determined that is characteristic of the vitality state of the cell.