Abstract: A bend sensor for measuring a deflection of a technical or medical instrument, consisting of an elongated body of electrically insulating polymer material, with a longitudinal axis and with fibers of an electrically conducting polymer material that are embedded in the body. The fibers are disposed essentially parallel to the longitudinal axis and at a distance from one another in the polymer body. A measuring unit is connected with the fibers and is suited for evaluating the modification of the electrical resistances of the fibers as a measurement of the deflection of the body from the longitudinal axis.