165 results about "Percolation threshold" patented technology

An electro-optic display comprises first and second substrates, and an adhesive layer and a layer of electro-optic material disposed between the first and second substrates. The adhesive layer has a volume resistivity in the range of about 10<9 >to about 10<11 >ohm cm and comprises a mixture of an adhesive material having a volume resistivity of at least about 5x10<11 >ohm cm and a filler having a volume resistivity not less than about 10<7 >ohm cm, the filler being present in the mixture in a proportion above its percolation threshold in the adhesive material.

Electrical, thermal and mechanical applications are provided for nanocomposite materials having low percolation thresholds for electrical conductivity, low percolation thresholds for thermal conductivity, or improved mechanical properties.

An electro-optic display comprises first and second substrates, and an adhesive layer and a layer of electro-optic material disposed between the first and second substrates. The adhesive layer has a volume resistivity in the range of about 109 to about 1011 ohm cm and comprises a mixture of an adhesive material having a volume resistivity of at least about 5x1011 ohm cm and a filler having a volume resistivity not less than about 107 ohm cm, the filler being present in the mixture in a proportion above its percolation threshold in the adhesive material.

Methods for preparing composite materials containing carbon nanotubes and a matrix material are provided. Nanotube composite materials and electrical devices made using nanotube composite materials are also provided. Composite materials composed of nanotubes near the percolation threshold provide electrical conductivities greater than about 10−9 S / cm.

A method for forming a body comprising a mixture of a matrix and conductive particles, whereby the conductive particles are formed into aligned conductive pathways in an alignment step by applying an electric field between alignment electrodes and thereafter stabilizing the mixture wherein the conductive particles have a low aspect ratio; and a polymeric composition and method for producing such composition which is curable by UV light to an anisotropic electrically conductive polymer layer, comprising i) providing a non-conductive matrix of a flowable polymer composition having inherent photocurability, ii) adding to matrix conductive particles having low aspect ratio in an amount to allow the concentration of the conductive particles to be maintained at a level lower than the percolation threshold, and iii) placing the formed composition in a receptacle where exposure to UV light is prevented, and a method for establishing an anisotropic electrically conductive, optionally thermally conductive

A high-sensitivity pressure conduction sensor is presented. The present invention includes a pair of locally resilient conductive layers and a locally resilient pressure conduction composite disposed between and contacting both conductive layers. Alternate embodiments include at least three locally resilient conductive layers and at least two locally resilient pressure conduction composites, each having a critical percolation threshold. Each composite is disposed between and contacting two conductive layers in a multi-layer fashion. Other embodiments include a locally resilient pressure conduction composite, a flexible substrate completely surrounding the composite so as to seal it therein, and a pair of electrical leads contacting the composite and terminating outside of the flexible substrate. Pressure conduction composites are composed of a plurality of conductive particles electrically isolated within a non-conductive matrix. Conductive particles are loaded so as to have a volume fraction approaching the critical percolation threshold of the material system and exhibit a conductance that greatly increases with pressure. Sensors may be arranged to form one or more arrays including planar and conformal configurations. The present invention has immediate application in keyboards, intrusion systems, control systems, submarines, ships, sonobuoys, doors, and switches.

A technique of forming a metallurgical bond between pads on two surfaces is provided. A metal coating placed on each surface includes a first metal base layer and a second metal surface layer. The first and second metals include a low melting point constituent. A first ratio of the two metals forms a liquid phase with a second ratio of the two metals forming a solid phase. The volume of the base layer metal exceeds the volume necessary to form the solid phase between the base metal and the surface metal. Conductive metal particles are provided having a core metal and a coating metal dispersed in an uncured polymer material, at a volume fraction above the percolation threshold. The core metal and the coating metal together include a low melting point constituent. At a first ratio the components form a liquid phase and at a second ratio the two components form a solid phase. The polymer containing particles is placed between the two metal surfaces with the particles interfacing with each other and the surface layer of metal. The structure is heated to a temperature higher than the low melting liquid constituent to form a liquid phase which extends to include the surface of the pads and the surface of the particles, and thereafter form a solid phase by diffusion of the core material into the surface material and the base metal into the coating material.

The presently described embodiments provide electric paper, in one form, that is bisymmetrical, both sides of the paper have the same thicknesses of mylar layers and the same thicknesses and patterns of ITO islands. In another form, a disordered layer of conductive particles, non-conductive particles and display elements has the same percolation threshold throughout, and thus is bisymmetrical. In either form, in a system for printing all asymmetries in the printing process are transferred to the printhead, just like in conventional ink printers and paper. As a result, both sides of the electric paper are equally capable of being printed on, just like conventional paper, and the electric paper has the same flexural properties when flexed in a concave or convex manner, just like conventional paper. This construction has the additional practical advantage that there is no longer any need to ensure the electric paper is oriented “right side up” before printing on it. These improvements all make electric paper more paper-like in feel and use.

An electrode for interventional purposes, such as a cardiac pacemaker, neurostimulation, or ICD electrode, comprises an elongate electrode body (6), at least one electrode pole (5) in the area of the distal end (4) of the electrode body (6) for delivering an intervention pulse, at least one supply line (7) running in the electrode body (6) to the at least one electrode pole (5), and an electrode sheath (8) for insulating the supply line (7). The first and / or second material is produced in such a way that it contains conductive particles embedded in a polymer matrix in a concentration which is greater than or equal to the percolation threshold.

A polyamide composition which provides moldings having a significantly reduced percolation threshold and an improved electrical conductivity is provided. The composition contains a) at least 40 parts by weight of a polyamide; b) from 0.15 to 25 parts by weight of an electrically conductive carbon; c) from 0.3 to 8 parts by weight of an oligofunctional compound; and, optionally, d) conventional auxiliaries and additives, wherein the electrically conductive carbon comprises at least one of carbon nanotubes and graphene, the oligofunctional compound comprises at least one functional group reactive with reactive groups on a surface of the electrically conductive carbon and at least one functional group reactive with an end group of the polyamide, and the sum of the parts by weight of the components a) to d) is 100.