Variable-airflow cloth, sound absorbing material, and vehicular part

Cloth in which air permeability is variable by energization, the cloth comprising:

• a fibrous object comprising composite fibers, the composite fibers comprising:
• an electrical-conductive polymeric fiber formed of an electrical-conductive polymeric material;
• and a polymeric fiber formed of a material different from the electrical-conductive polymeric material, the polymeric fiber being in direct contact with and formed on a surface of the electrical-conductive polymeric fiber, wherein the fibrous object is allowed to shrink in response to an electrical current supplied through the electrical-conductive polymeric fiber;
• electrodes which are attached to the fibrous object, and through which an electric current flows to the electrical-conductive polymeric fiber;
• and
• a power supply which applies the electric current to the electrical-conductive polymeric fiber through the electrodes,
• wherein the composite fibers have a structure in which the polymeric fiber is stacked on at least a part of a surface of the electrical-conductive polymeric fiber, or a structure in which either one of the electrical-conductive polymeric fiber and the polymeric fiber penetrates the other fiber in a longitudinal direction,
• wherein when the power supply applies the electric current to the electrical-conductive polymeric fiber, the electrical-conductive polymeric fiber shrinks, and the electrical-conductive polymeric fiber causes a length difference from the polymeric fiber, and
• wherein the composite fibers are arranged such that an air permeability or a sound absorption of the cloth is changed when the power supply applies the electric current.