Abstract: The operational frequency of existing magnetoelectric materials having metallic or ceramic magnetostrictive materials and ceramic piezoelectric materials may be limited to a few kilohertz due to the presence of eddy-current losses in the metallic magnetostrictive phase. Further, these materials may be difficult to machine and fabricate due to their brittleness. Additionally, it may be difficult to tailor and optimize the properties (i.e., magnetoelectric voltage coefficient ?E, etc.) of the devices. This invention provides a magnetoelectric element including at least one set of alternating piezoelectric layers and magnetostrictive composite layers. The magnetostrictive composite layer includes at least one magnetostrictive material dispersed in first concentrated zones within a first polymer matrix, wherein all of the concentrated zones are orientated along a first direction. It is found that the conversion efficiency (i.e., ?E) varies in accordance with applied magnetic control field Hcontrol.

Abstract: An magnetorheological damper useful in structural vibration control has a damper body and a moveable portion relative to the damper body. The damper includes an magnetorheological material contained within the damper body for resisting movement of the moveable portion. Rheology changes can be generated in the magnetorheological material owing to changes in a magnetic field, to which the magnetorheological material is exposed. The damper further includes at least a sensor embedded in the damper for monitoring an external force exerted on the damper, and for generating a signal to control the magnetic field and hence the resulting yield force and rheological damping of the damper in response to a variance in the external force.

Abstract: A tunable vibration absorption device is provided that is suitable for active or semi-active vibration absorption or damping of vibrations in vibrating structures. It comprises a stack including a force actuator mechanism for generating an axial actuation force and a force sensor mechanism which is responsive to an external force acting on the stack to generate a force signal. A controller unit is electrically connected to the force sensor mechanism for receiving the force signal generated by the force sensor mechanism, and it is also electrically connected to the force actuator mechanism for adjusting the axial actuation force generated by the force actuator mechanism in response to the received force signal generated by the force sensor mechanism.

Abstract: A piezoelectric device is provided that comprises a mechanical amplifier adapted to produce a displacement output and/or receive a force input, and first and second flexible platforms connected to the mechanical amplifier. The first flexible platform is connected to one side of the mechanical amplifier and piezoelectric material is mounted on the first flexible platform for controllably flexing the first flexible platform. The second flexible platform is connected to another side of the mechanical amplifier and piezoelectric material is mounted to the second flexible platform for controllably flexing the second flexible platform.

Abstract: Existing magnetoelectric materials relying on the use of metallic or ceramic magnetostrictive materials and ceramic piezoelectric materials as their constituent phases may have three problems. First, the operational frequency may be limited to a few kilohertz due to the presence of eddy-current losses in the metallic magnetostrictive phase. Secondly, it may be difficult to machine and fabricate devices due to the mechanical brittleness of the ceramic and some metallic magnetostrictive phases as well as of the ceramic piezoelectric phase. Thirdly, it may be difficult to tailor and optimize the properties (i.e., magnetoelectric voltage coefficient ?E, etc.) of the devices due to the limitation of the types of the constituent materials. This invention provides a magnetoelectric element including at least one set of alternative piezoelectric layer and magnetostrictive composite layer.

Abstract: An ultrasonic transducer driver has a giant magnetostrictive element, a fastener for holding the giant magnetostrictive element under mechanical pressure, a first field generator for providing a magnetic bias field, a second field generator for providing a magnetic drive field and a magnetic circuit for channelling the magnetic fields in the magnetostrictive element. An ultrasonic transducer for a bonding apparatus has a horn having a bonding tool at its smaller end and a mounting barrel adjoined onto it. The driver coupled to the larger end of the horn.