Electroactive polymer devices for moving fluid

#The present invention relates generally to electroactive polymer devices that convert between electrical energy and mechanical energy. More particularly, the present invention relates to pumping devices comprising one or more electroactive polymer transducers.

#Fluid systems are ubiquitous. The automotive industry, the plumbing industry, chemical processing industry, computer industry, refrigeration/cooling industry, home appliance industry, and the aerospace industry are a few examples where fluid systems are of critical importance. In most fluid systems, it is often desirable to perform thermodynamic work on the fluid in the fluid system. The thermodynamic work, such as in the case of a pump or fan, may be used to provide the energy needed to move the fluid in the fluid system from one location to another location in the fluid system. As another example, the thermodynamic work may be used to place the fluid in a desirable thermodynamic state, such as compressing the fluid in a refrigeration system to convert it from a gas phase to a liquid or compressing the fluid in a combustion system prior to combustion such as in an automobile engine. In yet another example, thermodynamic work may be performed on a fluid as a means of energy transfer, such as in a hydraulic lift or hydraulic control system.

#In general, pumps, fans and compressors have wide ranging applications in both the home and industrial environment. 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. Pumps and compressors are also used widely in biomedical applications including, for example, circulating blood for dialysis or during surgical procedures.

#FIGS. 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.

#FIGS. 2A–2D illustrate Electroactive Polymer (EPAM) devices that use a flagella-like motion for performing thermodynamic work on a fluid.

#FIGS. 2E–2F illustrate Electroactive Polymer (EPAM) devices with a bellows for performing thermodynamic work on a fluid.

#The present invention is described in detail with reference to a few preferred embodiments as illustrated in the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art, that the present invention may be practiced without some or all of these specific details. In other instances, well known process steps and/or structures have not been described in detail in order to not unnecessarily obscure the present invention.

#1. Electroactive Polymers

#In section, before describing electroactive polymer (EPAM) devices of the present invention for performing thermodynamic work on a fluid, the basic principles of electroactive polymer construction and operation will first be illuminated in regards to FIG. 1A and FIG. 1B. In section 2, embodiments of devices and systems with EPAM transducers and their operation, such as pumps, compressors, fans and hydraulic cylinders are described with respect to FIGS. 2A–2K and 3A–3J. In section 3, embodiments of EPAM transducers of the present invention are described in regards to FIGS. 4A–4N. In section 4, sensing applications are described. In section 5, conditioning electronics of the present invention are described with respect to FIGS. 5A and 5B. In section 6, a few examples of applications such as biological applications, automobile applications and printing applications, are described.