Abstract: An ultrasonically welded joint is made by placing a thermoplastic film (5) between two thermoplastic members (10, 20). The two thermoplastic members each have a mating part of a complex joint. One part of the joint, known as the shear joint (40), serves to shear away part (6) of the film when the two members come together, and another section of the same joint, known as the mash joint (30), serves to bond the film and the two members all together during the ultrasonic welding process.

Abstract: A very thin fuel cell (500) is formed by stacking a plurality of membrane electrode assemblies (MEA) (210) and a plurality of double sided distribution plates (220). The distribution plates serve to distribute fuel and oxidant to the MEAs, and they are electrically and thermally conductive and gas impermeable, and have fuel and oxidant distribution channels formed on opposite sides. The oxidant flowing through the oxidant distribution channels also provides thermal management to the fuel cell, eliminating the need for a separate heat exchange system. The MEAs and the distribution plates are arranged in an alternating stack (200) such that the fuel distribution channel side (315) is in intimate and direct contact with the MEA anode (212), and such that the oxidant distribution channel (415) is in intimate and direct contact with the MEA cathode (214). The distribution plate acts as a bipolar plate and also as a heat exchanger.

Abstract: A planar fuel cell (20) is provided, including a membrane electrode assembly (23) sandwiched between two current collector assemblies (21, 22). The membrane electrode assembly is a single sheet of a polymer electrolyte membrane with an array of anodes (27) on one side and an array of corresponding cathodes (28) on the other side. The current collectors (25) can be supported by a plastic frame (24), and they have an interconnect tab (26) that provides an electrical pathway to the exterior of the membrane electrode assembly. The interconnect tab is situated to provide electron transfer between the anodes and the cathodes such that the interconnect tab does not traverse the thickness of the polymer electrolyte membrane. When the planar fuel cell is assembled, the interconnect tab is sealed to prevent leaking of fuel or oxidant gases. Fuel is distributed (36) to only one side of the membrane electrode assembly and oxidant is distributed (36) only to the other side.

Abstract: A fuel cell (30) has an internal fuel source (35) that is in a matrix around a membrane electrode assembly (29). The membrane electrode assembly is constructed to be generally formed in the shape of a solid cylinder. The fuel cell has a porous central core (22) of reticulated vitreous metal that is formed in the shape of a solid cylinder. The porous central core serves to distribute oxidant throughout the fuel cell. A cathode (23) is situated coaxially around the porous central core, and has a catalytic layer on the outer side. A solid polymer electrolyte (25) is situated coaxially around the cathode and in intimate contact with the catalytic layer. An anode (27) is situated coaxially around the electrolyte, and a second layer of catalytic material is situated between the electrolyte and the anode. A housing (31) contains the internal fuel supply and holds the membrane electrode assemblies in place.

Abstract: A fuel cell (20) can be constructed to be generally formed in the shape of a solid cylinder. The fuel cell has a porous central core (22) of reticulated vitreous aluminum that is formed in the shape of a solid cylinder. The porous central core serves to distribute oxidant throughout the fuel cell. A cathode (23) is situated coaxially around the porous central core, and has a catalytic layer (24) on the outer side. A solid polymer electrolyte (25) is situated coaxially around the cathode and in intimate contact with the catalytic layer. An anode (27) is situated coaxially around the electrolyte, and a second layer of catalytic material (26) is situated between the electrolyte and the anode. A fuel chamber (28) is situated coaxially around and in intimate contact with the anode and arranged to distribute fuel throughout the fuel cell.

Abstract: An optical switch assembly for a two-way radio has electrical and mechanical subassemblies. The electrical portion consists an IR emitter (12) and a pair of IR receivers (14,16) strategically positioned upon a printed circuit board (10). The mechanical portion consists of a rotatable interposer mechanism (20) interconnected to a knob (35) on the radio via a shaft (28). The interposer has inner (22) and outer (24) concentric cylindrical walls. The outer wall controls the light transmitted between the emitter and one of the receivers (16), ultimately controlling the On-Off state of the radio. The inner wall has an integrated gray-scale graphic which controls the transmission of light between the emitter and the other IR receiver (14), ultimately controlling the audio output of the radio.

Abstract: A control switch for a radio is formed using an electro-mechanical assembly (400) which includes an array of cantilevered beams (402) laminated with piezoelectric film. A movable surface (404) includes protrusions (406) positioned to deflect the cantilevered beams and generate pulsed signals in a coded manner. Electronic circuitry (410) stores the pulsed signals and associates the signals with a position of the switch.

Abstract: A rapid method for fabricating a tooling die insert (71) is disclosed. A set of master parts (31, 32) in the shape of the insert is formed using stereolithography or other rapid prototyping techniques (106). The master parts are assembled and a flexible material is molded (109, 56, 57) in them to form a flexible mold (111, 61). The flexible mold is then filled (115) with metal powder and the powder is cold isostatically pressed (117) to solidify it and form a green part. The "green part" is then hot isostatically pressed (118) to form the densifyed tool.

Abstract: A communication device is designed to contain the lowest possible level of toxic or hazardous materials, so that when it is eventually disposed of, it will not harm the environment and can be safely recycled. Each component A.sub.1, A.sub.2, . . . , A.sub.n in the communication device has a calculated Component Toxicity Index value. A Product Toxicity Index for the entire communication device is calculated by summing the individual Component Toxicity Index values. The desired outcome is a communication device having a Product Toxicity Index less than or equal to 100. The resulting communication device is referred to as "environmentally friendly". The communication device may be a two-way radio (10), and some of the components are a radio transmitter (12), a radio receiver (14), an antenna (16), an amplifier (18), a battery (20) and a housing (22).

Abstract: A rapid method for fabricating a precision electrical discharge machining (EDM) electrode (71). A set of master parts (31, 32) in the shape of the EDM electrode is formed using stereolithography or other rapid prototyping techniques (106). The master parts are assembled and a flexible material is molded (109, 56, 57) in them to form a flexible mold (111, 61). The flexible mold is then filled (115) with electrically conductive powder and the powder is cold isostatically pressed (117) to solidify it and form the EDM electrode.

Abstract: A method of fabricating an elastomeric keypad having a hard key cap over the elastomeric key. A sheet (50) containing a key cap (24) with graphics (26) is placed onto a first plate (52) of a molding tool (54). A second plate (58) is then attached to the first plate, covering the graphic film. The first plate and the second plate interact in a manner such that the key cap containing the graphic is excised out of the film and retained in the molding tool assembly. The waste material (60) surrounding the key cap is displaced away from its original position. A third plate (64) is then attached to the assembled first and second plates. The assembled molding tool creates a cavity (66) that is representative of the keypad assembly, and an elastomeric material is molded into that cavity. Afar the elastomeric material (12) solidifies, the tool is opened, the molded keypad assembly (10) containing the integrally attached rigid key caps is removed.