Abstract: The invention relates to a particle injector for introducing particles into a carrier flow of a microfluidic system, especially for injecting biological cells into the carrier flow of a cell sorter. The particle injector includes an inlet for receiving the carrier flow, an outlet for discharging the carrier flow including the introduced particles, a carrier flow channel which connects the inlet to the outlet, and an injection channel flowing into the carrier flow channel for introducing the particles into the carrier flow. The inventive particle injector is characterized in that the carrier flow channel has substantially no dead volume.

Abstract: A fiber laser with a fiber for laser light generation having an entrance end and an exit end comprises a pump light source for generating pump light to be coupled via the entrance side into the fiber. At the exit end of the fiber a first resonator mirror is provided which is highly reflecting for the laser light to be generated in the wavelength range with the smallest light amplification and to the light of the pump light source. Spaced from the first resonator mirror a second resonator mirror is provided via which light of further wavelength ranges can be fed back into the fiber with the aid of a collimating lens.

Abstract: For the cell trace based testing of biological cells, wherein the cells (16) are applied to an at least partially structured and/or surface modified substrate (11) and move adhesively over surface track regions (13, 15) of the substrate while producing cell traces (14a, 14b) consisting of material residues separated from the cells, cell tests are performed on the cell traces. A process for cell cultivation on biocompatible modified substrates whose surfaces are covered by cell traces is also described.

Abstract: In order to isoelectrically separate particles with a pH-dependent net charge, the particles are exposed in a guiding liquid to electric field forces. The pH value of the guiding liquid is set in such a way that at least one predetermined type of particle is separated from the remaining particles and migrates to a fixing collecting means under the effect of the electric field forces. The collecting means is for example a porous hollow fiber delimited by electrodes which generate the electric field forces and crossed by the guiding liquid together with the sample to be separated. The particles whose isoelectric point matches the pH value of the guiding liquid run unimpeded through the fibers, whereas the remaining particles are pressed against the inner wall of the fiber and are prevented from being carried away with the liquid flow.

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: The aim of the invention is to convectively move at least one liquid in a channel of a microsystem which comprises a predetermined channel direction. To this end, the liquid is, in a partial section of the channel, subjected to an electric field gradient and optionally to a thermal gradient. The gradients are generated in the partial section corresponding to a predetermined field direction, whereby the field direction differs from the channel direction.