Abstract: Piezoelectric elements are attached to both sides of a flexible metal thin plate, thus forming a bimorph-type piezoelectric vibrator. A portion of the metal thin plate is extended to form a stirring blade. A suitable weight is attached to a part of the metal plate such that the amplitude of the blade is made greater than the amplitude of the vibrator itself. The voltage to be applied to the vibrator and the frequency are adjusted, and the vibrator is vibrated in a second-order mode. Thereby, the entire solution is moved simultaneously, vertical motion is caused, and the stirring efficiency is enhanced.

Abstract: A stirring apparatus for an automatic chemical analysis system for analyzing a sample in a reaction vessel for obtaining an amount of a specific component of the sample. The stirring apparatus includes a stirring member formed as a vibrating member of a piezoelectric vibrator and having a flexible structure in the shape of an elongated strip or plate, a support unit for holding the stirring member in a perpendicularly suspended manner, a moving unit for moving the support unit together with the stirring member between the reaction vessel and a washing unit for washing the stirring member, a vibrating unit for vibrating the stirring member in a washing pool of the washing unit and in the reaction vessel and a control unit operatively connected to these units, respectively, for controlling operations of the respective units.