Abstract: A honeycomb structure has a substantially circular-pillar-shape. The honeycomb structure includes at least one electrically conductive honeycomb unit, a first electrode, and a second electrode. The at least one electrically conductive honeycomb unit includes walls extending along a longitudinal direction of the at least one electrically conductive honeycomb unit to define a plurality of through holes. The first electrode is provided on an outer circumferential surface of the honeycomb structure. The second electrode is provided in a vicinity of a central axis of the honeycomb structure extending along the longitudinal direction.

Abstract: A honeycomb structural body includes a plurality of honeycomb units adhered to each other by interposing an adhesive layer. Each of the honeycomb units has a substantially fan shaped cross section or a substantially elliptical fan shaped cross section perpendicular to a longitudinal direction of each of the honeycomb units. First and second electrodes are provided at a part of an outer peripheral surface of each of the honeycomb units that does not face the adhesive layer and are provided at a first area between each of the honeycomb units and the adhesive layer. And/or the first and second electrodes are provided at a second area between the outer peripheral surface of each of the honeycomb units and the adhesive layer and are provided at a third area including a center of the substantially fan shaped cross section or the substantially elliptical fan shaped cross section.

Abstract: A honeycomb structural body includes a plurality of honeycomb units, first and second electrodes, and first and second conductive members. The plurality of honeycomb units are adhered to each other by interposing an adhesive layer. Each of the plurality of honeycomb units contains a conductive ceramic material. Each of the plurality of honeycomb units includes cell walls extending along a longitudinal direction of each of the plurality of honeycomb units to define a plurality of through-holes. The first and second electrodes are provided on an outer peripheral surface of each of the plurality of honeycomb units. The first and second conductive members are electrically connected to the first and second electrodes, respectively.

Abstract: A honeycomb structure includes at least one honeycomb unit. The at least one honeycomb unit includes a pair of electrodes and cell walls. The cell walls extend along a longitudinal direction of the at least one honeycomb unit to define a plurality of through holes. The cell walls have pores filled with a substance under a formation region of the pair of electrodes. The substance has an electrical resistivity lower than an electrical resistivity of a material to form the at least one honeycomb unit.

Abstract: A honeycomb structural body includes a plurality of honeycomb units adhered to each other by interposing an adhesive layer. Each of the honeycomb units has a substantially fan shaped cross section or a substantially elliptical fan shaped cross section perpendicular to a longitudinal direction of each of the honeycomb units. First and second electrodes are provided at a part of an outer peripheral surface of each of the honeycomb units that does not face the adhesive layer and are provided at a first area between each of the honeycomb units and the adhesive layer. And/or the first and second electrodes are provided at a second area between the outer peripheral surface of each of the honeycomb units and the adhesive layer and are provided at a third area including a center of the substantially fan shaped cross section or the substantially elliptical fan shaped cross section.

Abstract: A honeycomb structural body includes a plurality of honeycomb units, first and second electrodes, and first and second conductive members. The plurality of honeycomb units are adhered to each other by interposing an adhesive layer. Each of the plurality of honeycomb units contains a conductive ceramic material. Each of the plurality of honeycomb units includes cell walls extending along a longitudinal direction of each of the plurality of honeycomb units to define a plurality of through-holes. The first and second electrodes are provided on an outer peripheral surface of each of the plurality of honeycomb units. The first and second conductive members are electrically connected to the first and second electrodes, respectively.

Abstract: A honeycomb structure has a substantially circular-pillar-shape. The honeycomb structure includes at least one electrically conductive honeycomb unit, a first electrode, and a second electrode. The at least one electrically conductive honeycomb unit includes walls extending along a longitudinal direction of the at least one electrically conductive honeycomb unit to define a plurality of through holes. The first electrode is provided on an outer circumferential surface of the honeycomb structure. The second electrode is provided in a vicinity of a central axis of the honeycomb structure extending along the longitudinal direction.

Abstract: A honeycomb structure includes at least one pillar-shaped honeycomb unit and a pair of electrodes. The pillar-shaped honeycomb unit includes an outer peripheral wall and cell walls. The cell walls extend along a longitudinal direction of the honeycomb unit to define cells. The cell walls are composed of a ceramic aggregate having pores. The cell walls contain a substance having an electrical resistivity lower than an electrical resistivity of ceramic forming the ceramic aggregate. The pair of electrodes is arranged at the cell walls and/or the outer peripheral wall.