US Patent 7712832 Vehicle seat with variable firmness

A vehicle seat includes a frame, a flexible cover, and a material that is sufficiently mounted with respect to the flexible cover such that the material resists displacement of at least part of the flexible cover with respect to the frame. The material is characterized by a first state in which the material is characterized by a first rigidity, and a second state in which the material is characterized by a second rigidity that is greater than the first rigidity. Thus, the firmness of the seat is selectively variable by causing the material to change between the first and second states. A corresponding method is also provided.