Abstract: The invention relates to a method for checking the state of a pipette, which pipette includes a suction tube and a pipette tip. According to the invention, ultrasound is coupled into the wall of the suction tube and the damping of the ultrasonic signal is measured as a function of the frequency. The measured frequency-dependent damping is compared with at least one reference measurement or a calibration curve based on the reference measurements, in order to determine whether the pipette is in a functional condition and/or whether the pipette contains or has made contact with fluid. Furthermore, the invention relates to a pipetting method which uses the inventive method for checking the state, a suction tube arrangement for a pipetting device for pipetting fluid, and a pipetting device with which the inventive methods can be carried out.

Abstract: The invention relates to a method for generating motion in a thin liquid film on a substrate, in particular in a capillary gap, in which at least one ultrasound wave is sent right through the substrate in the direction of the liquid film, and a device for carrying out the inventive method.

Abstract: A method for treating extremely small particles of recycled polyethylene terephthalate comprises providing a quantity of RPET particles having an average mean particle size ranging from about 0.0005 inch to about 0.05 inch in diameter, heating the RPET particles to a temperature sufficient to cause at least a portion of the RPET particles to adhere to one another, and forming the adhered RPET particles into pellets, said pellets having substantially the same average surface-to-volume ratio as the bulk, un-adhered RPET particles.

Abstract: The invention relates to a method for checking the state of a pipette, which comprises a suction tube and a pipette tip. According to the invention, ultrasound is coupled into the wall of the suction tube and the damping of the ultrasonic signal is measured as a function of the frequency. The measured frequency-dependent damping is compared with at least one reference measurement or a calibration curve based on the reference measurements, in order to determine whether the pipette is in a functional condition and/or whether the pipette contains or has made contact with fluid. Furthermore, the invention relates to a pipetting method, which uses the inventive method for checking the state, a suction tube arrangement for a pipetting device for pipetting fluid and a pipetting device, with which the inventive methods can be carried out.

Abstract: The invention relates to a method for thoroughly mixing liquids in at least one microcavity using sound-induced flow, in which by means of at least one piezoelectric ultrasonic transducer at least one ultrasound wave of a frequency greater than or equal to 10 MHz is sent through a solid-body layer extending in the direction of sound propagation, which is greater than ¼ of the wavelength of the ultrasound wave, for generating a sound-induced flow into the at least one microcavity, and a device for carrying out the method according to the present invention.