US7064472B2 – Electroactive Polymer Devices For Moving Fluid – Google Patents

In one embodiment, the fluid conduit 335 may include an expansion valve that induces a phase change, such as from a liquid state to a gaseous state, which is common in refrigeration systems. The peristaltic pumping device 340 includes a fluid conduit 335 with an inlet 342 and exit 343 and a plurality of EPAM diaphragms 341 located on the inner surface of the fluid conduit 335. The diaphragms arrays may be individually controlled to generate a wave like motion, i.e., a peristaltic motion that propels fluid from the inlet 342 to the exit 343. For instance, the diaphragms may be deflected as a function of time starting from inlet 342 and progressing to the exit. Therefore, additional gearing may be required to use energy from the motor at a rate different from its optimal operating condition. Pat. No. 6,882,086 which is incorporated herein by reference in its entirety for all purposes which claims priority under 35 U.S.C.

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DISCARTROSIS DEFINICION PDF The portions of electroactive polymer 22 and spring 24 between end pieces 27 and 28 may be considered active to their functional purposes. The transformation between electrical and mechanical energy in devices of the present invention is based on energy conversion of one or more active areas of an electroactive polymer.

Tipos De Dolor Dental

FIG. 4L shows the outermost layer of polymer 182 and radially aligned active areas 184, 186, and 188, which are disposed such that their centers mark 90 degree increments relative to each other. The shape of the fan blade may be changed by deflecting one or more of the active areas on the EPAM transducer 391. Dolor en la lumbar derecha . EPAM transducers with a plurality of active areas are described with respect to FIGS. Open loop control 138 provides a passive (no external energy supplied) dynamic response for stiffness applied by transducer 132. Namely, the stiffness provided by transducer 132 may be set by the electrical components included in system 130, such as the control electronics and voltage source 134, or by a signal from control circuitry 136 acting upon one of the electrical components. In one embodiment, the resistor has a high resistance such that the RC time constant of open loop control 138 and transducer 132 connected in series is long compared to a frequency of interest.

The support plates are 303 are connected via a plurality of EPAM transducers 302. The bladder 312 is surrounding by a force return mechanism 311, such as a coil spring. The tire pump may be connected to a sensor control system in the automobile. For instance, the pump 350 may be used to pump fuel, such as to pump fuel in a fuel cell or fuel for combustion in a combustion chamber. For instance, if the support structures are located above a heat source, the radial motion generated by the pump 305 could be used to move a heated fluid away from the heat source. For instance, the heat source may be a microprocessor. FIGS. 3A and 3B illustrate a first embodiment of an EPAM tube-type pump device 350. The tube pumping device may comprise one or more electroactive polymer transducers. Thus, the flatness parameter for this embodiment is proximately 0.035. Device for performing thermodynamic work of the present invention with a flatness parameter much less than this value are also feasible, such as less than 0.01. For devices where space is at a premium, like electronic devices such as laptop computers, the ability to produce a device for performing thermodynamic work with a small flatness parameter may be advantageous.

The spring-type biasing may be suitable for low-power applications. Fixing or securing the polymer after rolling, along with the substantially constant outer dimensions for spring 24, maintains the circumferential prestrain about spring 24. In one embodiment, polymer 22 has a circumferential prestrain from about 100 to about 500 percent. For example, one might have the compression stroke of one stage coincide with the expansion stroke of the next stage. The clamp plate and lower chamber may serve as a housing for the device or the clamp plate and lower chamber may be enclosed in a separate housing. The fluid may be used for conducting heat energy from a first location to a second location in the second device. In particular embodiments, the deflection of the portion of the electroactive polymer may change the one surface from a first shape to a second shape. The device may be used in a thermal control system for controlling a temperature at one or more locations in a second device.

Pre-strain of a polymer may be described, in one or more directions, as the change in dimension in a direction after pre-straining relative to the dimension in that direction before pre-straining. 1A and 1B illustrate a top view of a transducer portion before and after application of a voltage, respectively, in accordance with one embodiment of the present invention. In one embodiment, common electrode 177 comprises aluminum foil disposed on polymer 172 before rolling. In one embodiment, transducer 180 comprises four leads that provide common actuation for each of the four radially aligned active area sets.

Dolores Musculares En Los Brazos

In one embodiment, deflection is input into an active area sensor in some manner via one or more coupling mechanisms. Dolor de rodilla osgood-schlatter . Electroactive elastomers may exhibit high energy density, stress, and electromechanical coupling efficiency. The transducer portion 10 comprises a portion of an electroactive polymer 12 for converting between electrical energy and mechanical energy. FIGS. 3I and 3J illustrate an embodiment of a multi-stage EPAM compressor or pumping device. FIG. 6 is a schematic of a sensor 450 employing a transducer 451 according to one embodiment of the present invention. FIG. 4L illustrates a rolled transducer 180 capable of two-dimensional output in accordance with one environment of the present invention. 4L, or greater, or a deflection minimally away from the position shown in FIG.

The deflection of the portion of the electroactive polymer causes a change in a volume of the chamber. Sensing electronics 460 are in electrical communication with the electrodes of transducer 451 and detect the change in electrical energy or characteristics of transducer 451. In addition to detection, sensing electronics 460 may include circuits configured to detect, measure, process, propagate, and/or record the change in electrical energy or characteristics of transducer 451. Electroactive polymer transducers of the present invention may behave electrically in several ways in response to deflection of the electroactive polymer transducer. Spring 24 also maintains circumferential prestrain on polymer 22. Dolor detras de la rodilla izquierda . The prestrain may be established in polymer 22 longitudinally in direction 33 (FIG. With high pre-strain, the diameter of the tube will be contracted in the central portion due to Poisson contraction (not shown in FIG. In FIG. 2C, four EPAM transducers 302 are arranged to direct a fluid radially inward to a location that is proximately central to the four transducers.

Tecnicas De Relajacion

Other methods for biasing diaphragm-type transducers include the use of a bias material 397, such as foam, pressure (or vacuum), and a swelling agent (e.g., a small amount of silicone oil). As examples, pumps, fans and/or compressors are used for circulating refrigerant and removing waste heat in cooling systems (e.g., air conditioning, refrigeration), pumping water in washing machine and dishwashers, removing waste heat from heat sources (e.g., CPU) in the computing industry, pressurizing air for pneumatic systems, transporting water for irrigation, transporting oil and gas in pipelines, and moving fluids between various unit operations in a chemical process plant.