Abstract: An electromechanical actuator 10 is disclosed, having drive elements (14a–d) movable in two dimensions and connected to an actuator backing (12). The actuator backing (12) is made of a material being ferromechanically inactive. Furthermore, the joint between the drive element (14a–d) and the actuator backing (12) is stiff and highly stable. This is achieved by use of an irreversible joint made e.g. by thermoset plastic glues, diffusion bonding or co-sintering. Co-sintering is to prefer. The actuator backing (12) material is selected to be stiff, preferably having a stiffness above 70 GPa and more preferably above 100 GPa, and having a high heat conductivity, preferably above 5 W/mK and more preferably above 10 W/mK, Electrodes (22) are preferably integrated in the actuator backing to increase stiffness as well as improving the heat conductivity. The drive elements (14a–d) are preferably covered (28, 26), at least at the driving surface, by heat-conducting material.

Abstract: In an electromechanical motor, elongated electromechanical drive elements are mechanically and preferably also electrically attached to a carrier. A spring is arranged to apply a force on the electromechanical drive element by pressing the backside of the carrier at a pivot point. The carrier is allowed to pivot around the pivot point around an axis parallel to a the element elongation. The electromechanical drive element is thereby suspended in a floating manner. The electromechanical drive elements are arranged to present a bending motion having strokes perpendicular to the elongation. The pivot point, the mechanical joint between the carrier and the electromechanical drive element, and preferably also a nodal point of bending motions of the electromechanical element are situated at a common plane perpendicular to the element elongation. In one embodiment, the electromechanical drive element is provided with metallizations to which the carrier is soldered.

Abstract: An electromechanical motor (1) has a driving element (30) comprising two electromechanical sections (32, 34) extended substantially parallel to a driving surface (14) of a body (10) to be moved. The electromechanical sections (32, 34) are rigidly supported by a backbone portion (22) of a stator (20) at a first end (38). An link member (40) having a single actuating portion (42), which by its interaction with the driving surface (14) of the body (10) moves the body (10), is attached between respective second ends (36) of the electromechanical sections (32, 34). The electromechanical sections (32, 34) are excitable in a vibration mode having strokes substantially perpendicular to the direction of motion (12). A portion of the link (40) or the joints (46, 54) between the link member (40) and the electromechanical sections (32, 34) have a bending stiffness in the direction of the strokes that is significantly lower than the bending stiffness of the electromechanical sections (32, 34) themselves.

Abstract: An electromechanical motor (1) has a driving element (20) comprising two electromechanical vibrators (22, 24). The two electromechanical vibrators (22, 24) are interconnected by a link member (26). The electromechanical vibrators (22, 24) are, at the ends (21, 23) connected to the link (26), attached to a backbone (12) of a stator (10) by a respective resilient joint member (14, 16). A mechanical connection to the backbone (12) is thus introduced essentially between the vibrator (22, 24) and the link (26). A vibration of one of the electromechanical vibrators (22, 24) is transferred into a tilting or torsion of one of the joint members (14, 16), and a similar vibration of the other electromechanical vibrator (22, 24) provides a tilting or torsion of the other joint member (14, 16). The liner (26), interconnecting the vibrators (22, 24) is subsequently caused to deform and move.

Abstract: According to the present invention, electromechanical motors are driven in such a way that contact portions of driving elements (10) are moved along smooth trajectories. The velocity is varied, the average velocity being lower during the time when the element (10) is in contact with a moving object (22) than during the contact free time. Preferably, the main displacement velocity component is non-negligible when switching between sets of elements (10). When stopping the motor, the actuating sets of elements (10) are brought into a voltage-free condition, one set at a time. The contact portions of the elements (10) are lapped with such an accuracy, that the normal force applied between the moving object and the stator (2) is large enough to cause elastic deformations of the stator (2) that are in the same order of magnitude or larger than the accuracy of the lapping.

Abstract: An electromechanical motor according to the present invention has a stator with a drive element consisting of two serially connected bending sections and a central drive pad, for actuating on a body to be moved. The drive element extends parallel to the body. The drive pad and/or the body is elastic. Preferably, the drive pad has a lower stiffness than the body. The elasticity of the drive pad allows an assimilation of a part of the travelling wave energy applied to the drive element. The backbone of the stator is arranged to restrict the drive element from being removed from the body, but at the same time allow the drive element to be translated towards the body and even leave the mechanical contact with the backbone for shorter periods of time. Support means are preferably designed with convex surfaces in order to allow self-centering of the different parts of the motor.

Abstract: A flexible printed circuit board, supports electronics components, wiring, mechanical and components of an electromechanical transducer also acts as a main structural member for the entire microsystem.

Abstract: In a method according to the present invention, charging and discharging of motor phases (10A, 10B) in an electromechanical motor is performed with a small voltage difference between the voltage source and the capacitive load of the motor phase (10A, 10B). This is accomplished by connecting a series of voltage sources (36), one at a time. Energy from the discharging operation is stored to be used in subsequent charging operations. In a device according to the present invention, the voltage sources (36) are preferably provided by means of capacitive or induction voltage step-up or step-down circuits. Preferably, switches (34) control the charging and discharging. In a preferred embodiment, the capacitance of one motor phase (10A) is used for storing charge resulting from the discharge from another motor phase (10B).

Abstract: The present invention uses the resilient behaviour of a flexible printed circuit board (10), both to mechanically clamp the components (20) in a permanent manner and to achieve good electrical contacts (24) between conducting parts (12) of the flexible circuit board (10) and the components (20). By cutting the flexible printed circuit board in such a manner that small tab-like, resilient members (12,16) are formed, the forces caused by elastically deformed resilient members (12,16) are usable both for mechanically fixing the components (20) and for causing an electrical contact (24). By choosing appropriate sizes of the resilient members (12,16), the relative strength of the spring force is increased, which even will be large enough to cause a plastic deformation of the material in the contact points (24) between the conducting resilient members (12) and the component contact members (22). In such a manner, soldering or gluing may be totally omitted.

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 motors using electromechanical, preferably piezoelectric, elements (30). The element (30) comprises at least two movable parts or displacement portions (32A, 32B) interconnected by a passive part (31). Each displacement section (32A, 32B) comprises at least one bimorph (33A, 33B), where the active volumes extend in parallel out from the passive part (31), and so are the electrodes (12) arranged between the electromechanical layers. The displacement portions (32A, 32B) are positioned in substantially the same plane and parallel to the body (20) to be moved. Contact portions are arranged at the central passive part (31) and at the displacement portions (32A, 32B). In one embodiment, the central contact portion is an actuating surface (34C) and the other are attaching portions (36A, 36B) for attachment to a stator (24). In another embodiment, the central contact portion is an attaching portion and the other are actuating surfaces.

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.

Abstract: This invention relates to an actuator or motor comprising an electromechanical material which alters its shape under the influence of an electrical voltage. Said actuator comprises at least a monolitic module (1,2) with electrodes integrated in said electromechanical material and in that the force or displacement due to the applied voltages is transferred, to the point to be actuated or moved by the shape change of the material, using at least two independent contact points. The invention also relates to a method for fabricating said actuator or motor.