Abstract: A system for accurately dispensing small droplets from a positive displacement pumps is actuated by a linear actuator. Preferably the linear actuator is a piezo-actuator. In a method to use the device the system pressure is stabilized before dispensing a plurality of droplets.

Abstract: An electromechanical rotating actuator arrangement (10) includes a stator (20), a rotor (30), a guide arrangement (50) and an object (40) to be moved. The stator (20) has electromechanically active actuators (22), exhibiting shape changes upon excitation, rigidly attached to a common stator block (24). The rotor (30) has a planar drive surface (32). The electromechanically active actuators (22) have a respective driving surface (26), situated in a common plane (27) parallel to the drive surface (32), for mechanical interaction with the drive surface (32) of the rotor (30). The object (40) to be moved is attached to the rotor (30), giving a rigid mechanical connection between the object (40) and the drive surface (32). The guide arrangement (50) is arranged for restricting translational motions of the rotor (30) perpendicular to the rotation axis (12). A method for driving an electromechanical rotating actuator arrangement (10) is also disclosed.

Abstract: An electromechanical rotating actuator arrangement (10) includes a stator (20), a rotor (30), a guide arrangement (50) and an object (40) to be moved. The stator (20) has electromechanically active actuators (22), exhibiting shape changes upon excitation, rigidly attached to a common stator block (24). The rotor (30) has a planar drive surface (32). The electromechanically active actuators (22) have a respective driving surface (26), situated in a common plane (27) parallel to the drive surface (32), for mechanical interaction with the drive surface (32) of the rotor (30). The object (40) to be moved is attached to the rotor (30), giving a rigid mechanical connection between the object (40) and the drive surface (32). The guide arrangement (50) is arranged for restricting translational motions of the rotor (30) perpendicular to the rotation axis (12).

Abstract: An electromechanical actuator arrangement (50) comprises an electromechanical motor (10) and a rail arrangement (35). The rail arrangement (35) has a rail (30) relative which the electromechanical motor drives in a main displacement direction (3). The electromechanical motor has electromechanically active actuators attached to a motor block (20) and are arranged to provide an actuating action against the rail. The rail arrangement has further at least one guide member (31) provided parallel to the main displacement direction. The guide members have a guiding surface (36) facing the motor block. The motor block in turn has guidance surfaces (37) facing the guiding surface of the guide members. The guiding surface or the guidance surface has a tangent line parallel to the main displacement direction.

Abstract: The present invention discloses an electromechanical actuator arrangement and a driving device for such an arrangement, having a plurality of drive element to be driven according to a wailing mechanism is provided. The driving device is characterised by an electrical power source (170) and at least two switches (172a, 172b) connected in series between the terminals (177) of the voltage source (170). An element terminal (178) is connected to a point (175) between said switches (172a, 172b), and a motor phase (174) of the actuator arrangement is connected to the element terminal (178). A control unit (171) is connected to control the switches (172a, 172b) in order to charge/discharge the drive elements. A charge control is thereby achieved by the use of the two switches (172a, 172b).

Abstract: The present invention discloses an electromechanical actuator arrangement (10) and a method for driving such arrangement, having a plurality of drive elements (14a-d) according to a walking mechanism in a motion relative a body (22). A driving portion of the drive elements (14a-d) are independent movable tangentially and normally to the body (22) surface. The drive elements (14a-d) are driven in the fours cycle steps; gripping, moving the body, releasing and returning to the original position. The drive elements (14a-d) are divided into two exclusive sets. The driving of the sets is phase shifted. At least one of the sets is in contact with the body (22) surface at each instant. The present invention is characterised in that the driving of the drive elements (14a-d) during the gripping sequence is performed in such a way that the drive elements (14a-d) have a velocity, which has a significant tangential component.