Conductive structures
AssigneePeratech Limited
InventorDavid Lussey
Life of this patent
Estimating the term…
Abstract
A conductive structure is used in electric variable resistance devices to provide changes in electrical resistance with movement and changes in pressure, the variable resistance device comprising externally connectable electrodes (10) bridged by an element (14) containing polymer and particles of metal, alloy or reduced metal oxide, said element (14) having a first level of conductance when quiescent and being convertible to a second level of conductance by change of stress applied by stretching or compression or electric field, the device further comprising by means (18) to stress the element (14) over a cross-sectional area proportional to the level of conductance required.
Claims28
A variable electrical conductance composite having a first level of electrical conductance when quiescent and a second level of conductance upon change of mechanical or electrical stress applied to said composite, said composite comprising a collapsible body of an insulating or weakly conductive material containing interstices that contain granules of an insulating or weakly conductive polymer containing particles of at least one strongly conductive material selected from the group consisting of metals, alloys and reduced metal oxides, said granules having such a loading of said strongly conductive material that said granules themselves have a first level of electrical conductance when quiescent and a second level of conductance upon change of mechanical or electrical stress applied to said granules.
A variable resistor having a first level of electrical conductance when quiescent and a second level of conductance upon change of mechanical or electrical stress applied to said resistor, said resistor comprising externally connectable electrodes bridged by a collapsible body of an insulating or weakly conductive material containing interstices that contain granules of an insulating or weakly conductive polymer containing particles of at least one strongly conductive material selected from the group consisting of metals, alloys and reduced metal oxides, said granules having such a loading of said strongly conductive material that said granules themselves have a first level of electrical conductance when quiescent and a second level of conductance upon change of mechanical or electrical stress applied to said granules.
A chemical sensor comprising:
- a) a contacting head including a variable resistor having a first level of electrical conductance when quiescent and a second level of conductance upon change of mechanical or electrical stress applied to said resistor, said resistor including externally connectable electrodes bridged by a collapsible body of an insulating or weakly conductive material containing interstices that are accessible to mobile fluid and contain granules of an insulating or weakly conductive polymer containing particles of at least one strongly conductive material selected from the group consisting of metals, alloys and reduced metal oxides, said granules having such a loading of said strongly conductive material that said granules themselves have a first level of electrical conductance when quiescent and a second level of conductance upon change of mechanical or electrical stress applied to said granules,
- b) means for access of a mobile fluid containing the chemical to be sensed to the head, and
- c) means to connect the electrodes into an electrical circuit effective to detect a variation in conductance of said resistor.
Dependencies are inferred from the claim text.