Nicolas Szita

A fast and low-volume pipettor with integrated sensors for high precision

This paper describes the design and the measurement results of a new micropipetting device for the pipetting of biological liquids. The device has been designed for precise, accurate and fast pipetting in the micro- and submicroliter range. It contains a precision pipetting head with two integrated sensors realised in silicon bulk micromachining to ensure precision and accuracy and a coupled piezo disk-type actuator to fulfil the force requirements of fast pipetting. Measurements in open-loop mode showed pipetting of 0.5 to 2 /spl mu/l with a CV between 1 and 7%. Closed-loop control of the actuator can eliminate the piezoactuators hysteresis and drift and further increase precision and accuracy.

Aspiration and Dispensing of Biological Liquids in the Micro- and Submicroliter Range with High Precision

This paper describes the design and the fabrication as well as the measurement results of a new micropipetting device designed for the pipetting of biological liquids in the micro- and submicroliter range. The device is a modular set-up including a precision pipetting head with two integrated sensors realized in silicon bulk micromachining and a coupled piezo disk-type actuator to fulfil the force and stroke requirements for fast pipetting. With this device we have pipetted water from 0.4 to 2.7 μl and serum from 0.45 μl to 3.1 μl. The measurements were undertaken in open-loop mode and the coefficients of variation for repeated pipetting cycles were below 4%. Due to the integrated sensors the system can be expanded to a closed-loop system to compensate for the piezoactuators hysteresis and drift, thus further increasing precision and accuracy.