Cushioning for a seating or backrest portion of a motor vehicle seat

A cushioning for a seating or backrest portion of a motor vehicle seat, the cushioning comprising:

• an elastically compressible material-based padded block,
• a cap for covering the block,
• a heating layer being inserted between the block and the cap, the layer comprising an electric circuit made from conductive ink, the ink being based on a polymer binder wherein are dispersed conductive particles, the ink being printed on a support, the cushioning having the following features:
• the circuit comprises at least one first and at least one second bus extending longitudinally,
• the first bus is provided with a first connection point intended to be connected to a first pole of an electrical generator and the second bus is provided with a second connection point intended to be connected to a second pole of the generator, the connection points being located along an edge of the cushioning,
• the buses are connected together by a plurality of printed microcircuits shaped to form resistances capable of heating the cushioning by flow of an electrical current,
• the cushioning wherein it furthermore has, as required, either one of the following features:
• the buses are made from a first ink and the microcircuits are made from a second ink, the first ink having a higher intrinsic conductivity than that of the second ink,
• or the buses and microcircuits are made from one same ink, the ink being deposited more thickly for the buses than for the microcircuits, such that the buses provide minimised electrical resistance to the flow of current.