Patent attributes
A sensor yarn (10) having a thread core (11) around which first and second conductors (12, 13) are helically wound. The two conductors (12, 13) are electrically insulated from each other and from the thread core (11). The two conductors (12, 13) form a capacitive component (15) together with the thread core (11). In one embodiment, the sensor yarn (10a) has a capacitance (Cl) per unit of length that changes in the direction of extent (E) of the sensor yarn. This can be accomplished by a change in the winding geometry of the first or second conductors (12, 13) or by a change of the relative permittivity (E) of the sensor yarn (10). In another embodiment, the sensor yarn (10b) has photosensitive material (30) and a length change is effected by an incident to the light (L). As a result of a length change or other deformation of the sensor yarn (10a, 10b), the total capacitance (CG) of the sensor yarn (10a, 10b) changes, which can be determined by means of an evaluating unit (17).
