Disclosed is a self-contained device which continuously dispenses a packaged fluid. The device is particularly suited for applications where several months may lapse before performance is manually initiated, after which a consistent steady flow is required for an extended period until the packaged fluid is exhausted. The device is also particularly suited for applications where ease of fabrication and where availability of materials are important factors. A button cell battery provides a driving force to reduce atmospheric oxygen at a simple air cathode, ions are transported through an ion-exchange membrane, and oxygen gas is released at a simple anode. The effective transport of oxygen gas pressurizes a chamber resulting in fluid contained in a flexible bladder within the chamber to be forced through an outlet. This device is intended to be very low in cost and thus disposable.
RELATED APPLICATIONS
This application is a continuation-in-part of U.S. application Ser. No. 08/058,438, filed May 7, 1993, U.S. Pat. No. 5,454,922, entitled "Fluid Dispensing Pump" pending and commonly assigned. The specification of such prior application is hereby incorporated by reference.
A fluidic pump (108) comprises an electrolyte cavity (110) and a pump outlet (115) fluidically coupled to the electrolyte cavity that are within at least a portion of a fluid guiding structure (105), two electrodes (112, 113) extending from the fluid guiding structure into the electrolyte cavity; and a vapor permeable membrane (120) that prevents an electrolyte (125) in the electrolyte cavity from passing through the pump outlet while allowing gas to flow through the pump outlet.
An anode catalyst layer for a fuel cell is presented having first and second catalyst compositions and a hydrophobic binder. The first catalyst composition includes a noble metal, other than Ru, on a corrosion-resistant support material; the second catalyst composition contains a single-phase solid solution of a metal oxide containing Ru. The through-plane concentration of ionomer in the catalyst layer decreases as a function of distance from the membrane interface. Gas diffusion electrodes, catalyst-coated membranes, MEAs and fuel cells having the foregoing anode catalyst layer are also described.
A storage stable fluid delivery device including a gas generator in which moisture (water) is involved in the gas generation reaction in which moisture containment is utilized to prevent or retard water loss as disclosed. The moisture containment may be a moisture impermeable membrane as a permanent part of the device and may be utilized in conjunction with the gas generator when the membrane has high gas permeability for the gas being generated. The fluid delivered by such device is typically a liquid having some particular utility in its environment. The liquid dispensed may be a pharmaceutical or some other liquid having a beneficial or curative effect upon an animal or human patient or it may be a liquid such as an insecticide, fumigant, fragrance or other liquid having a relatively high vapor pressure.
