Patent ID: 8890649

Claim:
A bending sensor comprising: a base material; a sensor body arranged on a surface of the base material and containing a matrix resin and conductive filler particles, the conductive filler particles being 30% by volume or more of the matrix resin, and in which three-dimensional conductive paths are defined by contact among the conductive filler particles and when a deformation amount of the sensor body increases, an electrical resistance increases; an elastically deformable cover film arranged so as to cover the sensor body; a strain adjustment plate arranged on a rear surface of the base material; an adhesion layer bonding the strain adjustment plate and the base material; and a plurality of electrodes connected to the sensor body and capable of outputting electrical resistances, wherein cracks are provided in the sensor body along such a direction that the conductive paths are cut off during a bending deformation of the sensor body, the cracks being pre-formed on the sensor body by a deformation of a precursor of the sensor body along a mold surface of a mold for crack formation, and the base material, the strain adjustment plate, and the adhesion layer are all made from materials having a glass-rubber transition region, in which a storage elastic modulus transitions, on one of a lower temperature side than a lower temperature limit of an operating temperature range of the bending sensor minus 10° C., or on a higher temperature side than an upper temperature limit of the operating temperature range of the bending sensor plus 10° C., and a pre-determined strain is provided in a bending direction in the sensor body.