Abstract: A chemiresistor sensor probe for detecting target analytes. The probe includes a body having a first control surface and a second control surface recessed within the first. A sensor film comprises numerous conductive particles disposed upon the second surface. The film swells upon absorbing one or more analytes for which it has an affinity, thus causing the conductive particles to become more dispersed and increasing the resistance between the particles. The thickness of the film is equal to the distance between the first surface and the second surface, thus permitting the thickness to be controlled by varying the distance between the control surfaces. The robustness of the sensor probe is enhanced by placing a porous or mesh electrode along with, or in place of, a chemical binding agent between the film and the terminals. The robustness is also improved by placing a diode in series with the sensor circuit.

Abstract: A chemiresistor sensor probe for detecting target analytes. The probe includes a body having a first control surface and a second control surface recessed within the first. A sensor film comprises numerous conductive particles disposed upon the second surface. The film swells upon absorbing one or more analytes for which it has an affinity, thus causing the conductive particles to become more dispersed and increasing the resistance between the particles. The thickness of the film is equal to the distance between the first surface and the second surface, thus permitting the thickness to be controlled by varying the distance between the control surfaces. The robustness of the sensor probe is enhanced by placing a porous or mesh electrode along with, or in place of, a chemical binding agent between the film and the terminals. The robustness is also improved by placing a diode in series with the sensor circuit.

Abstract: The present invention relates to a composition for sensor films used for detecting chemical analytes within sensors, such as polymer-absorption chemiresistors (i.e. conductometric sensors). The present invention provides sensor film compositions that have greater temperature stability and sensitivity to chemical analytes, as well as methods of making these sensor films. Sensor film compositions according to the present invention include a crosslinked siloxane polymer comprising a monomer having a hydrocarbon side group with greater than or equal to two carbon atoms and a plurality of conductive particles distributed within the polymer. Alternate preferred embodiments distribute an oil comprising siloxane having at least one side group with greater than or equal to two carbons through a crosslinked siloxane polymer, wherein the oil is distributed through a crosslinked polysiloxane copolymer.

Abstract: The invention provides polymeric PTC compositions and electrical PTC devices with higher voltage capability and improved electrical stability. The PTC compositions include at a minimum an organic polymer and a conductive filler including carbon black having an iodine adsorption of less than about 60 mg/g carbon and a dibutyl phthalate absorption of greater than about 115 cc/100 g. Depending on device design, the composition can be used in low to high voltage applications.

Abstract: The invention provides polymeric PTC compositions and electrical PTC devices with higher voltage capability and improved electrical stability. The PTC compositions of the present invention exhibit improved processability and include at a minimum an organic polymner, a conductive filler and a low molecular weight polyethylene processing aid. Depending on device design, the composition can be used in low to high voltage applications.

Abstract: The invention provides polymeric PTC compositions and electrical PTC devices with higher voltage capability and improved electrical stability. The PTC compositions include at a minimum an organic polymer and a conductive filler including carbon black having an iodine adsorption of less than about 60 mg/g carbon and a dibutyl phthalate absorption of greater than about 115 cc/100 g. Depending on device design, the composition can be used in low to high voltage applications.

Abstract: The invention provides polymeric PTC compositions and electrical PTC devices with higher voltage capability and improved electrical stability. The PTC compositions include at a minimum an organic polymer and a conductive filler including carbon black having a mean particle diameter of at least about 110 millimicrons and a dibutyl phthalate absorption of less than about 100 cc/100 g. Depending on device design, the composition can be used in low to high voltage applications.

Abstract: The invention provides polymeric PTC compositions and electrical PTC devices with high voltage capability and high switch temperatures. The polymeric PTC composition specifically includes perhydrotriphenylene as an organic polymer component which, when blended with a crystalline or semi-crystalline organic polymer component such as polyethylene, gives rise to a composition having a melting point, Tm of up to about 181° C.

Abstract: The invention provides polymeric PTC compositions and electrical PTC devices with higher voltage capability and improved electrical stability. In particular, the PTC compositions and devices include surface treated kaolin clay which has been found to improve voltage capabilities and give rise to an enhanced PTC effect.

Abstract: The invention provides polymeric PTC compositions and electrical PTC devices with a high voltage capability and improved electrical stability. The polymeric PTC compositions are readily blended and generally do not require cross-linking, particularly radiation induced cross-linking in order to manufacture useful products.

Abstract: The invention provides polymeric PTC compositions and electrical PTC devices with higher voltage capability and improved electrical stability. Depending on device design, the composition can be used in low to high voltage applications 6 volts up to 240 volts.