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Johnson, San Leandro

A. David Johnson, San Leandro, CA US

Patent application numberDescriptionPublished
20090171294Single crystal shape memory alloy devices and methods - Devices and methods of making devices having one or more components made of single crystal shape memory alloy capable of large recoverable distortions, defined herein as “hyperelastic” SMA. Recoverable Strains are as large as 9 percent, and in special circumstances as large as 22 percent. Hyperelastic SMAs exhibit no creep or gradual change during repeated cycling because there are no crystal boundaries. Hyperelastic properties are inherent in the single crystal as formed: no cold work or special heat treatment is necessary. Alloy components are Cu—Al—X where X may be Ni, Fe, Co, Mn. Single crystals are pulled from melt as in the Stepanov method and quenched by rapid cooling to prevent selective precipitation of individual elemental components. Conventional methods of finishing are used: milling, turning, electro-discharge machining, abrasion. Fields of application include aerospace, military, automotive, medical devices, microelectronics, and consumer products.07-02-2009

Patent applications by A. David Johnson, San Leandro, CA US

Alfred Johnson, San Leandro, CA US

Patent application numberDescriptionPublished
20100025050Frangible Shape Memory Alloy Fire Sprinkler Valve Actuator - A temperature-activated valve for a conventional fire sprinkler utilizing a hyperelastic single-crystal shape memory alloy is described. The shape-memory element expands as it is heated, forcing a bolt to break, thereby opening the sprinkler valve. The devices described are less susceptible to accidental breakage than conventional actuators, and have fewer moving parts. Transition temperature of the shape memory alloy can be tuned to a narrow range. 02-04-2010

Alfred David Johnson, San Leandro, CA US

Patent application numberDescriptionPublished
20080213062CONSTANT LOAD FASTENER - Described herein are fasteners and devices for securing together several components so that the load applied to the components is constant or nearly constant. The fasteners described herein include a hyperelastic member having first end to which a first retainer is coupled and a second end to which a second retainer is coupled. The retainers are configured to contact the structures being fastened and transfer the load from the structures to the hyperelastic member. The hyperelastic member may be an elongate shaft (e.g., a rod, cylinder, strut, etc.), and is a shape memory alloy that is typically fabricated as a single crystal.09-04-2008
20090035859METHOD AND DEVICES FOR PREVENTING RESTENOSIS IN CARDIOVASCULAR STENTS - Described herein are devices and methods fabricating devices having nanostructures that allow adhesion or growth of one cell type, such as endothelial cells, more than another cell type, such as smooth muscle cells. In particular, stent covers having such nanostructures are described, and methods for fabricating these stent covers. Also described herein are methods for optimizing the nanostructures forming the devices.02-05-2009
20090095493FRANGIBLE SHAPE MEMORY ALLOY FIRE SPRINKLER VALVE ACTUATOR - A temperature-activated valve for a conventional fire sprinkler utilizing a hyperelastic single-crystal shape memory alloy is described. The shape-memory element expands as it is heated, forcing a bolt to break, thereby opening the sprinkler valve. The devices described are less susceptible to accidental breakage than conventional actuators, and have fewer moving parts. Transition temperature of the shape memory alloy can be tuned to a narrow range.04-16-2009
20090139613HYPERELASTIC SHAPE SETTING DEVICES AND FABRICATION METHODS - Shape-setting methods for fabricating devices made of single crystal shape memory alloys. The method include drawing a single crystal of a shape memory alloy from a melt of the alloy. This is followed by heating and quenching the crystal sufficiently rapid to limit the formation of alloy precipitates to an amount which retains hyperelastic composition and properties of the crystal.06-04-2009
20090187243BIOCOMPATIBLE COPPER-BASED SINGLE-CRYSTAL SHAPE MEMORY ALLOYS - We describe herein biocompatible single crystal Cu-based shape memory alloys (SMAs). In particular, we show biocompatibility based on MEM elution cell cytotoxicity, ISO intramuscular implant, and hemo-compatibility tests producing negative cytotoxic results. This biocompatibility may be attributed to the formation of a durable oxide surface layer analogous to the titanium oxide layer that inhibits body fluid reaction to titanium nickel alloys, and/or the non-existence of crystal domain boundaries may inhibit corrosive chemical attack. Methods for controlling the formation of the protective aluminum oxide layer are also described, as are devices including such biocompatible single crystal copper-based SMAs.07-23-2009
20100006304SPRINKLER VALVE WITH ACTIVE ACTUATION - A temperature-activated valve for a conventional fire sprinkler utilizing a hyperelastic single-crystal shape memory alloy is described. The shape-memory element expands as it is heated, forcing a bolt to break, thereby opening the sprinkler valve. The shape memory element typically communicates with the valve so as to force it open. The devices described are less susceptible to accidental breakage than conventional actuators, and have fewer moving parts. Transition temperature of the shape memory alloy can be tuned to a narrow range.01-14-2010
20110083767HYPERELASTIC SHAPE SETTING DEVICES AND FABRICATION METHODS - Shape-setting methods for fabricating devices made of single crystal shape memory alloys. In particular the methods described may be used to fabricate dental arches of single-crystal shape memory alloys. The methods include drawing a single crystal of a shape memory alloy from a melt of the alloy. This is followed by heating, forming, and quenching the crystal sufficiently rapid to limit the formation of alloy precipitates to an amount which retains hyperelastic composition and properties of the crystal.04-14-2011

Patent applications by Alfred David Johnson, San Leandro, CA US

Craig Johnson, San Leandro, CA US

Patent application numberDescriptionPublished
20110092784ADJUSTABLE CONNECTOR AND DEAD SPACE REDUCTION - Methods and systems for determining the concentration of one or more analytes from a sample such as blood or plasma are described. The systems described herein can be configured to withdraw a certain volume of sample from a source of bodily fluid, direct a first portion of the withdrawn sample to an analyte monitoring system and return a second portion of the sample to the patient. The analyte monitoring system can be connected to the source of bodily fluid via a connector that is configured to maintain uniform velocity across the connector and reduce the dead space volume.04-21-2011