11120results about "Piezoelectric/electrostrictive devices" patented technology

A telemetry system and method for providing spatial positioning information from within a patient's body are disclosed. The system includes at least one implantable telemetry unit which includes (a) at least one first transducer being for converting a power signal received from outside the body, into electrical power for powering the at least one implantable telemetry unit; (b) at least one second transducer being for receiving a positioning field signal being received from outside the body; and (c) at least one third transducer being for transmitting a locating signal transmittable outside the body in response to the positioning field signal.

Various embodiments are directed to an apparatus and method of driving an end effector coupled to an ultrasonic drive system of a surgical instrument. The method comprises generating at least one electrical signal. The at least one electrical signal is monitored against a first set of logic conditions.

The invention describes rolled electroactive polymer devices. The invention also describes employment of these devices in a wide array of applications and methods for their fabrication. A rolled electroactive polymer device converts between electrical and mechanical energy; and includes a rolled electroactive polymer and at least two electrodes to provide the mechanical / electrical energy conversion. Prestrain is typically applied to the polymer. In one embodiment, a rolled electroactive polymer device employs a mechanism, such as a spring, that provides a force to prestrain the polymer. Since prestrain improves mechanical / electrical energy conversion for many electroactive polymers, the mechanism thus improves performance of the rolled electroactive polymer device.

A hybrid memory system having electromechanical memory cells is disclosed. A memory cell core circuit has an array of electromechanical memory cells, in which each cell is a crossbar junction at least one element of which is a nanotube or a nanotube ribbon. An access circuit provides array addresses to the memory cell core circuit to select at least one corresponding cell. The access circuit is constructed of semiconductor circuit elements.

Piezoelectric resonators utilizing a differentially offset reflector. One or more piezoelectric resonators are supported upon a substrate by one or more intervening layers of material, which intervening layers of material act as a reflector. The reflector isolates the resonators from the substrate. A portion of one or more of the intervening layers of material includes a differential layer of material, which differential layer shifts the resonant frequencies of the resonators that overlie the differential layer as compared with the resonant frequencies of those resonators that do not overlie the differential layer of material.

A method of forming a MEMS device includes depositing a conductive material on a substructure, forming a first sacrificial layer over the conductive material, including forming a substantially planar surface of the first sacrificial layer, and forming a first element over the substantially planar surface of the first sacrificial layer, including communicating the first element with the conductive material through the first sacrificial layer. In addition, the method includes forming a second sacrificial layer over the first element, including forming a substantially planar surface of the second sacrificial layer, forming a support through the second sacrificial layer to the first element after forming the second sacrificial layer, including filling the support, and forming a second element over the support and the substantially planar surface of the second sacrificial layer. As such, the method further includes substantially removing the first sacrificial layer and the second sacrificial layer, thereby supporting the second element relative to the first element with the support.

Electromechanical circuits, such as memory cells, and methods for making same are disclosed. The circuits include a structure having electrically conductive traces and supports extending from a surface of the substrate, and nanotube ribbons suspended by the supports that cross the electrically conductive traces, wherein each ribbon comprises one or more nanotubes. The electro-mechanical circuit elements are made by providing a structure having electrically conductive traces and supports, in which the supports extend from a surface of the substrate. A layer of nanotubes is provided over the supports, and portions of the layer of nanotubes are selectively removed to form ribbons of nanotubes that cross the electrically conductive traces. Each ribbon includes one or more nanotubes.

A piezoelectric device connected to a vibration source converts vibration energy to electrical current. A plurality of pairs of oppositely polarized piezoelectric wafers deflect to produce an electrical current. Each pair of wafers are arranged back-to-back and electrically joined together. The plurality of pairs of wafers are each connected to a set of micro-machined parts. Each pair of wafers form a bimorph, configured as a cantilevered beam attached to a set of parts to form an element. Each cantilevered beam has a mass weighted first end and is fixedly attached to one or more flexible sheaths on a second end. A plurality of elements form a cell unit. A plurality of cell units form an array. The electrical current produced varies by the number of elements per cell unit, and / or with the number of cell units per array.

A microfluidic device comprises pumps, valves, and fluid oscillation dampers. In a device employed for sorting, an entity is flowed by the pump along a flow channel through a detection region to a junction. Based upon an identity of the entity determined in the detection region, a waste or collection valve located on opposite branches of the flow channel at the junction are actuated, thereby routing the entity to either a waste pool or a collection pool. A damper structure may be located between the pump and the junction. The damper reduces the amplitude of oscillation pressure in the flow channel due to operation of the pump, thereby lessening oscillation in velocity of the entity during sorting process. The microfluidic device may be formed in a block of elastomer material, with thin membranes of the elastomer material deflectable into the flow channel to provide pump or valve functionality.

A charge control circuit for controlling a micro-electromechanical system (MEMS) device having variable capacitor formed by first conductive plate and a second conductive plate separated by a variable gap distance. The charge control circuit comprises a switch circuit configured to receive a reference voltage having a selected voltage level and configured to respond to an enable signal having a duration at least as long as an electrical time constant constant of the MEMS device, but shorter than a mechanical time constant of the MEMS device, to apply the selected voltage level across the first and second plates for the duration to thereby cause a stored charge having a desired magnitude to accumulate on the variable capacitor, wherein the variable gap distance is a function of the magnitude of the stored charge.

A piezoelectric device for an ink jet print head that has a greater displacement at a low drive voltage. The ink-jet recording head includes a vibration plate, on which is mounted one or more piezoelectric devices that change the volumes of pressure chambers upon application of a voltage. The device is mounted at least on one face of a pressure chamber substrate that is to be filled with ink. Such piezoelectric device includes a second piezoelectric layer having a piezoelectric constant g of a constant value or higher; and a first piezoelectric layer having a dielectric constant of a specific value or higher. Since the piezoelectric constant d of the piezoelectric device correlates with the product of the largest piezoelectric constant g and the largest dielectric device of the piezoelectric devices, a piezoelectric constant d larger than in the conventional case, i.e., having a greater displacement, can be obtained.

The invention relates to systems that provide variable stiffness and / or variable damping using an electroactive polymer transducer. Systems described herein offer several techniques that provide variable and controlled stiffness and / or damping. A transducer may be implemented using open loop control, thereby providing simple systems that inactively deliver a desired stiffness and / or damping performance. Alternately, closed loop control techniques permit electroactive polymer transducer designs that actively adapt the stiffness and / or damping performance of a system. Further, transducers may be implemented in a device whose stiffness changes with deflection of the polymer.

A structure of a structure release and a manufacturing method are provided. The structure and manufacturing method are adapted for an interference display cell. The structure of the interference display cell includes a first electrode, a second electrode and at least one supporter. The second electrode has at least one hole and is arranged about parallel with the first electrode. The supporter is located between the first electrode and the second electrode and a cavity is formed. In the release etch process of manufacturing the structure, an etchant can pass through the hole to etch a sacrificial layer between the first and the second electrodes to form the cavity; therefore, the time needed for the process becomes shorter.

A determination is made whether a moving speed of a slider section with respect to a rod section in a piezoelectric actuator is lower than a predetermined speed. When the moving speed is lower than the predetermined speed, it is considered that a friction-bonded portion between the rod section and the slider section is in a fastened state or a nearly fastened state. A resonance frequency of the piezoelectric actuator or a frequency proximity to the resonance frequency is set as a driving frequency for the piezoelectric actuator. The slider section is moved in a reciprocating manner plural times with respect to the rod section. As a result, an abnormal state is eliminated from the piezoelectric actuator.

A drive unit being characterized in that a movable object can be prevented from being tilted when the movable object is stopped using a restricting member. The drive unit comprises a piezoelectric element, a rod provided at an end of the piezoelectric element, a movable object frictionally engaged with the rod, and drive pulse generating means that apply drive signals to the piezoelectric element. The drive pulse generating means apply to the piezoelectric element a rectangular wave drive signal that has a duty ratio other than 0.5 and vibrates the rod so that a difference occurs between the expansion and contraction of the rod when the movable object is moved, and apply to the piezoelectric element a rectangular wave drive signal that has a duty ratio of 0.5 and vibrates the rod so that the movable object is not moved substantially when it is detected that the movable object is in contact with a restricting member.

A first electrode and a sacrificial layer are sequentially formed on a substrate, and then first openings for forming supports inside are formed in the first electrode and the sacrificial layer. The supports are formed in the first openings, and then a second electrode is formed on the sacrificial layer and the supports, thus forming a micro electro mechanical system structure. Afterward, an adhesive is used to adhere and fix a protection structure to the substrate for forming a chamber to enclose the micro electro mechanical system structure, and at least one second opening is preserved on sidewalls of the chamber. A release etch process is subsequently employed to remove the sacrificial layer through the second opening in order to form cavities in an optical interference reflection structure. Finally, the second opening is closed to seal the optical interference reflection structure between the substrate and the protection structure.

The present invention provides a system and method of quantifying flow, detecting a location of an obstruction and quantifying a degree of the obstruction in a pipe characterized in pulsatile flow. The method includes the steps of (a) attaching at least two spaced pressure sensors onto inner walls of the pipe; (b) using the at least two spaced pressure sensors for recording pressure records associated with each of the at least two pressure sensors within the pipe; and (c) using the pressure records for quantifying the pulsatile flow in the pipe, for detecting the location of the obstruction in the pipe and for quantifying the degree of the obstruction in the pipe.

The disclosed fabrication methodology addresses the problem of creating low-cost micro-electro-mechanical devices and systems, and, in particular, addresses the problem of delicate microstructures being damaged by the surface tension created as a wet etchant evaporates. This disclosure demonstrates a method for employing a dry plasma etch process to release encapsulated microelectromechanical components.

An electronic component includes a semiconductor substrate having a first surface and a second surface opposite to the first surface, a cavity that penetrates from the first surface to the second surface of the semiconductor substrate, and an electrical mechanical element that has a movable portion formed above the first surface of the semiconductor substrate so that the movable portion is arranged above the cavity. The electronic component further includes an electric conduction plug, which penetrates from the first surface to the second surface of the semiconductor substrate, and which is electrically connected to the electrical mechanical element.

Nanotube films and articles and methods of making the same are disclosed. A conductive article includes an aggregate of nanotube segments in which the nanotube segments contact other nanotube segments to define a plurality of conductive pathways along the article. The nanotube segments may be single walled carbon nanotubes, or multi-walled carbon nanotubes. The various segments may have different lengths and may include segments having a length shorter than the length of the article. The articles so formed may be disposed on substrates, and may form an electrical network of nanotubes within the article itself. Conductive articles may be made on a substrate by forming a nanotube fabric on the substrate, and defining a pattern within the fabric in which the pattern corresponds to the conductive article. The nanotube fabric may be formed by growing the nanotube fabric on the substrate using a catalyst, for example, in which the catalyst is a gas phase catalyst, or in which the catalyst is a metallic gas phase catalyst. The nanotube fabric may be formed by depositing a solution of suspended nanotubes on the substrate. The deposited solution may be spun to create a spin-coating of the solution. The solution may be deposited by dipping the substrate into the solution. The nanotube fabric is formed by spraying an aerosol having nanotubes onto a surface of the substrate.

A method of fabricating an elastomeric structure, comprising: forming a first elastomeric layer on top of a first micromachined mold, the first micromachined mold having a first raised protrusion which forms a first recess extending along a bottom surface of the first elastomeric layer; forming a second elastomeric layer on top of a second micromachined mold, the second micromachined mold having a second raised protrusion which forms a second recess extending along a bottom surface of the second elastomeric layer; bonding the bottom surface of the second elastomeric layer onto a top surface of the first elastomeric layer such that a control channel forms in the second recess between the first and second elastomeric layers; and positioning the first elastomeric layer on top of a planar substrate such that a flow channel forms in the first recess between the first elastomeric layer and the planar substrate.

The present invention relates to transducers, their use and fabrication. The transducers convert between mechanical and electrical energy. Some transducers of the present invention include a pre-strained polymer. The pre-strain improves the conversion between electrical and mechanical energy. The present invention also relates to devices including an electroactive polymer to convert between electrical and mechanical energy. The present invention further relates to compliant electrodes that conform to the shape of a polymer included in a transducer. The present invention provides methods for fabricating electromechanical devices including one or more electroactive polymers.

The invention provides a micro-electro-mechanical-system (MEMS) mirror device, comprising: a mirror having a 2-dimensional rotational articulated hinge at a first end, and having a 1-dimensional rotational articulated hinge at a second end opposite the first end; a movable cantilever connected to the mirror through the 1-dimensional rotational articulated hinge; a support structure connected to the mirror through the 2-dimensional rotational articulated hinge and connected to the movable cantilever; whereby movement of said movable cantilever causes rotation of the mirror in a first axis of rotation, and the mirror is also rotatable about a second torsional axis of rotation perpendicular to said first axis of rotation.

The movement and mixing of microdroplets through microchannels is described employing microscale devices, comprising microdroplet transport channels, reaction regions, electrophoresis modules, and radiation detectors. Microdroplets are metered into defined volumes and are subsequently incorporated into a variety of biological assays. Electronic components are fabricated on the same substrate material, allowing sensors and controlling circuitry to be incorporated in the same device.

The invention describes devices for performing thermodynamic work on a fluid, such as pumps, compressors and fans. The thermodynamic work may be used to provide a driving force for moving the fluid. Work performed on the fluid may be transmitted to other devices, such as a piston in a hydraulic actuation device. The devices may include one or more electroactive polymer transducers with an electroactive polymer that deflects in response to an application of an electric field. The electroactive polymer may be in contact with a fluid where the deflection of the electroactive polymer may be used to perform thermodynamic work on the fluid. The devices may be designed to efficiently operate at a plurality of operating conditions, such as operating conditions that produce an acoustic signal above or below the human hearing range. The devices may be used in thermal control systems, such as refrigeration system, cooling systems and heating systems.

An apparatus for driving a threaded shaft assembly that contains a threaded shaft with an axis of rotation and, engaged therewith, a threaded nut. Subjecting the threaded nut to ultrasonic vibrations causes the threaded shaft to simultaneously rotate and translate in the axial direction. The threaded shaft is connected to a load that applies an axial force to the threaded shaft.

A thin-film resonator having a seed layer and a method of making the same are disclosed. The resonator is fabricated having a seed layer to assist in the fabrication of high quality piezoelectric layer for the resoantor. The resonator has the seed layer, a bottom electrode, piezoelectric layer, and a top electrode. The seed layer is often the same material as the piezoelectric layer such as Aluminum Nitride (AlN).

A memory system having electromechanical memory cells and decoders is disclosed. A decoder circuit selects at least one of the memory cells of an array of such cells. Each cell in the array is a crossbar junction at least one element of which is a nanotube or a nanotube ribbon. The decoder circuit is constructed of crossbar junctions at least one element of each junction being a nanotube or a nanotube ribbon.