In certain embodiments, a method comprises ablating, by a laser set to a first power level, a first area of a polyimide base substrate and forming, by ablating the first area of the polyimide base substrate, a first carbonaceous material film comprising a first specific resistive value. The method further comprises ablating, by the laser set to a second power level, a second area of the polyimide base substrate and forming, by ablating the second area of the polyimide base substrate, a second carbonaceous material film comprising a second specific resistive value. A tapered resistive material is produced by forming the first carbonaceous material film comprising the first specific resistive value and the second carbonaceous material film comprising the second specific resistive value.

A passive two-terminal circuit element may include a resistor including a carbon-metal composite resistive element. The resistive element is configured to maintain a resistivity that fluctuates less than one tenth of an ohm per ten degree temperature change up to 400 degrees Celsius.

A conductive nanocomposite which contains a mixed polymer matrix which contains a rubber and a polyether, carbon nanoparticles, and transition metal nanoparticles. The conductive nanocomposite has a nonlinear relationship between resistivity and temperature characterized by an exponential increase reaching a peak resistivity followed by an exponential decrease as temperature increases. Also disclosed is a method of forming the conductive nanocomposite involving mixing the components, aging, and pressing. The conductive nanocomposite forms a component of a heater that is self-regulating as a result of the nonlinear relationship between resistivity and temperature of the conductive nanocomposite. The nanocomposite also forms a component of a thermistor.

A porous carbon has an I.sub.D/I.sub.G of 2.0 or more in a Raman spectrum measured by Raman spectroscopy with respect to the porous carbon wherein the I.sub.G is an accumulated intensity of a peak for G band around 1590 cm.sup.−1, and the I.sub.D is an accumulated intensity of a peak for D band around 1350 cm.sup.−1. The porous carbon has pores having a size of less than 1 μm. The porous carbon can be contained in a resin composition for producing a varistor element.

An organic resistor is provided. The organic resistor includes a rubber substrate and a conducting film disposed over the rubber substrate. The conducting film includes a composite of carbon nanotubes and a nickel phthalocyanine complex dispersed in one or more edible oil(s). The present disclosure also relates to a method of making the organic resistor using rubbing-in technology. The organic resistor of the present invention is environmentally friendly and ecologically clean.

A polymeric positive temperature coefficient (PPTC) device including a PPTC body, a first electrode disposed on a first side of the PPTC body, and a second electrode disposed on a second side of the PPTC body, wherein the PPTC body is formed of a PPTC material that includes a polymer matrix and a conductive filler, wherein the conductive filler defines 20%-39% by volume of the PPTC material.

A method of making a hot surface igniter is described. A silicon carbide composition that includes both fines fraction and a coarse fraction is sintered in a nitrogen and argon reducing atmosphere in a manner that controls the incorporation of nitrogen with in the lattice of recrystallized silicon carbide. The controlled incorporation of nitrogen in the lattice provides enhanced control over heating and electrical properties, while simultaneously achieving a lower surface area fully recrystallized structure for oxidation resistance and long service life.

A conductive nanocomposite which contains a mixed polymer matrix which contains a rubber and a polyether, carbon nanoparticles, and transition metal nanoparticles. The conductive nanocomposite has a nonlinear relationship between resistivity and temperature characterized by an exponential increase reaching a peak resistivity followed by an exponential decrease as temperature increases. Also disclosed is a method of forming the conductive nanocomposite involving mixing the components, aging, and pressing. The conductive nanocomposite forms a component of a heater that is self-regulating as a result of the nonlinear relationship between resistivity and temperature of the conductive nanocomposite. The nanocomposite also forms a component of a thermistor.

A composition, method, and system for directly printing and creating complete functional 3D electronic circuits and devices without any thermal or laser post-processing treatment, by using at least Triphenylamine (TPA) as a powder binding agent. The composition can have mechanical characteristics that allow it to be melted and extruded on a structure, and electrical properties that allow it to function as at least one of a conductor, insulator, resistor, p-type semiconductor, n-type semiconductor, or capacitor.

A composition, method, and system for directly printing and creating complete functional 3D electronic circuits and devices without any thermal or laser post-processing treatment, by using at least Triphenylamine (TPA) as a powder binding agent. The composition can have mechanical characteristics that allow it to be melted and extruded on a structure, and electrical properties that allow it to function as at least one of a conductor, insulator, resistor, p-type semiconductor, n-type semiconductor, or capacitor.